I have a 93 S-15 Jimmy.
It is stuck in 4WD.
When I first got the truck it was in 2WD and wouldn’t shift into 4wd. That was because the vacum hoses had burnt in two. Once those hoses were fixed, it worked beuatifully. Better than any 4WD I have ever had before this.
I have already checked the hoses, They are still intact. Although when I pulled one apart, some fluid came out. Like tranny fluid. There -was- vacum in the line.
It is an electric shift. Push the button, the vacum servos do their thing, and it goes into or out of 4WD.
Only now, if I push the button, I can make it go from 4 hi to 4 lo, or versy-visey. But NOT out of 4WD into 2WD.
It sits there and does it’s click click click stuff, but it never actually shifts out.
I can hear something in the area of the glove box clicking. If I get under the car and have someone else push the button, I can also hear clicking in the area of the transfer case.
But it never actually shifts out of 4WD.
Any ideas ?
I’ll add that the overdrive started to slip, several months ago, and has gotten a bit worse.
The 4WD shifting, started acting up about a month after I noticed the overdrive slipping.
If I could just get it shifted out of 4WD into 2WD, I’d drive it that way until I could afford to have it looked at. Does anyone have any idea how I can do that, manually ?
There is absolutely nothing about this in my Haynes manual.
When I drive it now, the best I can do is 4 hi. In 4 hi, it is difficult to steer. The turning radius is at least half again what it is when in 2WD. Anything over 40MPH, and I am feeling major vibration through the floorboards. It is eating a lot of gas. And I am smelling gear lube getting quite hot, if I drive more than a couple miles.
Anyone with any idea what the problem is ? And how to fix it ?
This is my first stop on the internet. I’ll research more, as time permits.
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Replies
Bad modulator; the thingy at the end of the hose where it meets the trans.
When are you gonna give up on that thing?
They were junk the day they were new.
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Best vehicle I have ever owned.I just spent some time learning about the basic 4wd system.IF I am correct this is the basic system and how it works...*There is an actuator located under the battery.*There is a toggle switch on the dash.*There is a vacum switch on the transfer case.*There are vacum lines between the "vacum ball" under the dash, and the vacum switch, and then again from the vacum switch to the actuator under the battery.*There is a cable from the actuator to the transfer case.~~~When you press the toggle switch on the dash, the vacum switch on the transfer case is activated. That lets vacum from the vacum ball, go through the vacum switch, to the actuator under the battery.When the actuator gets vacum, it pulls on the cable that goes back to the TC. That switches the 4WD drive on.~~~Now, if I am correct about all this, then I have a couple of other questions...1. Does the actuator pull on the cable only just so much, to switch the TC into 4hi, and then another just so much to switch it into 4lo ? Then let it back out halfway to go back to 4hi, and let it back out all the way to switch back to 2wd ???(I have to insert here that my haynes manual holds absolutely no information whatever on this entire system. And I have never laid hands or eyes on any electric 4wd system before in my life. If I am correct, it is only due to what I have read on the internet in these couple hours.)2. If the entire vacum systemn is bypassed, and I control that cable manually... will the TC still shift back and forth as normal, or does that vacum switch on the TC perform some other service besides just direct the vacum ?~~~IF I am correct.... And IF cutting out/bypassing the rest of the system... Then pulling on that cable manually will still shift the TC into 4wd normally...Then I already know I can make a very simple cable system to control that cable manually, from the driver's seat. And bypass any and all future problems with this entire system.All it will take is a salvaged hood release cable, or a choke cable available for less than 15 bucks... Some springs, some shelf brackets, nuts bolts, etc...My last concern would be whether it would mess with the computer in any way if that switch on the dash was no longer being used ?
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I thnk you have the answer, the modulator. If it's bad, (busted diaphragm) it will not work, and will suck fluid into the engine. This may cause the smell as well as other problems. I don't know, but you may be able to "jimmy" the modulator out of 4wd and plug the vacuum line. It just moves a lever in and out, and is externally accessible.
Do you guys actually know about this particular engine/TC/tranny, or are you just pulling my leg. LOL;o)It sounds to me like you guys are talking about another, simpler system.Ok, so what is at the TC is a 'modulator', not just a simple switch to turn the vacum on or off ?What exactly does this modulator do, besides let the vacum flow from the big black ball under the hood, through this 'modulator, and to the actuator that is under the battery ?Read again... the way I understand this system...1. flip the toggle switch at the dash.2. This activates the vacum switch on the TC.3 When the vacum switch is activated, it opens up and lets the vacum through.4. That vacum comes from the big ball under the hood. (And/or another line that I found on the back of the vortec, at the top of the engine.) It goes through the vacum switch, and then all the way back out to the actuator that is is under the battery tray.5. When the vacum reaches the actuator, the actuator pulls on a cable. That cable is what shifts the TC into and out of 4WD.~~~Now... the way I understand what youns are saying... You are talking about a device that sits on the TC, recieves vacum, and directly shifts the TC into and out of 4WD.If that is the case, it sounds like you are talking about oranges when I have a watermelon.
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Ok, to make things more complicated...It sounds like there is a motor inside the TC that does all the actual shifting.The cable that runs from the actuator, (under the battery tray), back to the TC, is what controls that motor that sits inside the TC, doing the actual shifting...~~~I have noticed that when you shift it into or out of 4high... Whatever it is, that is sitting on/in the TC, clicks twice. For either opration. Into or out of 4wd high.But it only clicks once for 4low.My original assumption was that the actuator pulls the cable or releases it, and all that did was the simple moving of that lever in or out, inside the TC.But the way it is described on a forum dedicated to this truck... It sounds like the actuator pulls twice, (and releases), to tell the inner shifter to go into or out of 4 high. And only pulls once to go into or out of 4 low.
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Edited 6/12/2007 7:31 am by Luka
Disconnect the front drive shaft.
Learn to spell vaccuum."Put your creed in your deed." Emerson
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
You are talking about a whole other beast.I have two front driveshafts. If I disconnect them, the front wheels will fold up under the car. Literally.Three different acceptable ways to spell vacum.vacumvacuumvacume
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My final post on this for now. I need to get some sleep. LOLWhat I have discovered...The click click up on the transfer case, and inside the passenger kick panel are the shift motor and the controller, respectively.You push the button on the dash. That puts power to the controller in the kick panel. That controller tells the shift motor on the transfer case to shift the TC into 4wd. There is a shaft inside the TC that activates the vacum switch that is on top of the TC. That vacum switch then allows vacum to get to the actuator that is under the battery tray. When that actuator gets vacum, it manipulates a shift collar and fork, via that cable it pulls, to engage the intermediate shaft and give the front differential power from the transfer case. The front axles are powered from the differential.~~~At this point...I can disengage the differential by letting that cable loose. Good for the front axles. But that will leave the transfer case in 4wd. And that is not going to be good for the TC.The only way to shift the transfer case out of 4wd is to remove the shift motor, and turn the inner shaft by hand until the front shaft spins freely. Not easy.Looks like the only thing to be done is to start at point a, take things apart until I find the problem, and fix it.At least now I know the parts, and roughly how they are put together.Doesn't look like a cheap fix, no matter what. (When are they ever, right ? LOL) That shift motor alone sells for 118.00 to over 200.00.Who knows. Maybe I'll even figure out a way to replace that shift motor with some sort of manual control. I know I can do the differential shift easily enough. (They even make a kit to do exactly what I was talking about doing. LOL 130 bucks or so. I could do it for just the 30.);o)Thanks for your help, guys.=0)
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"I have two front driveshafts. If I disconnect them, the front wheels will fold up under the car. Literally"
It if is coil spring in the front those are control arms.
Only one driveshaft to the front on every 4x4. Removing the front driveshaft is the best short term advise, you will end up cooking the front pumpkin oil at highway speeds on dry pavement.
It's torsion bars in the front.However, you are correct. The two front axles are 'half-shafts'...They are driven by the front differential.And while I haven't yet seen, (or at least haven't yet noticed), the driveshaft youns refer to between the TC and differential, I am sure it is there.And you are also right about cooking that oil. I was certainly smelling it.I was afraif of just that. And that is why I started looking for a solution immediately. The 4wd actually works in this truck. (Well, did work. LOL) Unlike all the other '4wd' vehicles I have ever owned. And I don't want to ruin it by ignoring this problem.
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Still taking the driveshaft out won't affect the axle shafts inside the diff. The carrier and Pinnion will still hold everything together. I have done this in my jeep before. I snapped my front drive shaft and drove it for a week without it. A friend of mine drove his for a week without the rear driveshaft. Had to leave it in four wheel so it became a front wheel drive jeep for that week. It is really a non issue
Just take the caps off the u-joint and leave it out. Mark it so you put it back in in-phase or you may get vibrations when you put it back on.
Understood, and agreed.Still, that is a bit of work that I hope to avoid.=0)If I can't get it to switch out of 4wd somehow, I simply won't be moving the truck again, until I can fix it.
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they are cv joints that go to the wheels. i have broken one and kept on drivin outa the mud hole .the torrsion bars are to raise the front end or lower .
Not exactly. I have a GMC allwheel drive van with the same front pumpkin as am S10 or a Jimmy, matter of fact when the pinion seal wore out at 160,000 miles, 168,000 miles of ALL TIME AWD. I put a pumpkin from a JImmy in it, it had less wear than another AWD box. Because it was selectable.I have since racked up another 90,000 miles on that pumkin, and it spins all the time. There are two axles up front,those are what Luka can't take out. And then if he did remove the Drive shaft, yup, all the oil goes bye-bye, and fried pumkin is lunch."you are dead a lot longer than you are alive"Noah Aaron MacKenzie, 1990.
HOw does the oil go away by removing the driveshaft. As long as you keep the pinnion in the pinnion seal wiill keep the oil in. Dont take out the pinnion just the driveshaft at the U-joint. All axles have two axle shafts
That van is the same chassis as the Jimmy and the S-series truck
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Yup...thats why I got a front box outta a Jimmy, less wear, cuz 4wd is slectable, not all time on.
Front box on mine wouldn't have been any better than yours. LOLThat diff was on all the time. (Until I recently disonnected it.)
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IIRC, junkyard salvage , was still around 500 bucks. Lord knows what a NEW one woulda cost!
I don't even want to think about it.Knock on wood !!!!I'm off to see the wi, er I mean to change the vacum switch.Pay no attention to the man behind the jack stand.
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Have at it, good luck.
I was talking about sour grapes, not watermelons. Sorry.
I'm guessing that I came across like sour grapes.If that is the case, it is I who should be saying I'm sorry.It's beginning to seem that whenever I become focused on something, I begin to come across as sour grapes in my posts.This time, it was being focused on finding the problem with a system that I have had absolutely no prior experience with.One other time that was significant enough for me to remember with regret quite often, I was very focused on trying to be as helpful as possible. Yet, I was taken as spewing sour grapes. Please accept my apology. It was not at all my intention, to come across that way.
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No prob. I haven't worked on a jimmy 4x4 system, but I have put a fuel pump and starter in one. That was some tough working space, almost ridiculous. Had to yank off parts that I shouldn't have had to to replace both. Then I found the fuel pump wasn't leaking, but the fuel line was cracked.
I have had bad vacuum modulators on transmissions that would suck the ATF out of the transmission, and misbehave in general.
So, anyway, don't replace stuff until you know it's bad.
What you describe about 'tough working space', is exactly what I am facing.
They used both standard and metric shoehorns and sardine tins, to put this truck together.
I am so not looking forward to taking all those extra parts off, just to get to the one small part I have to replace.
~~~
I have replaced modulators on turbo 350's as well. And yes, they would suck tranny fluid into the engine when the diaphram broke.
Here is a link to the vacum switch we are talking about.
Vacum switch.
Apparently, when the shift motor on the transfer case shifts it into 4wd, that little ball on the end gets either pushed in, or let out, and the vacum passage inside the switch it opened.
That vacum then activates the actuator that shifts the front differential into gear.
And also apparently... this vacum switch, while not a modulator, can still leak tranny fluid into the vacum line when the switch is broken.
I agree about not replacing anything until I know it's bad.
The vacum switch is bad. If it were not, there would be no tranny fluid in the vacum line.
The actuator... Well it would seem if that was bad, it would have let the cable back out, and the front differential would be shifted out of engagement with the front half-shafts. No ? Ok, well that is the hope I am going to stick with for now. LOL
The final problem, may be the shift motor on the TC. (Or maybe the controller in the kickpanel.)
In order of cost, the vacum switch is less than 20 dollars.
The actuator is around 50 dollars.
The shift motor is 118 to over 200 dollars.
I sure hope that shift motor is ok...
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The service mechanic's switch trick didn't work. (BTW: The amber light DOES flash several times, then stay on, to let you know it is in 4lo.)I got the computer codes.12 Diagnostic mode.32 EGR43 Knock sensor No codes for the 4wd system. So I will assume for now that that controller behind the kick panel, and the shift motor itself on the TC are ok.I removed the negative from the battery, and will leave it that way Until I am ready to leave.Leave ??? You ask ? LOLYes. I called and found the prefferred top speed for this truck in 4wd high. 45 MPH. They say you can go highway speed without damage to the system. But they prefer 45 as the highest speed.I am going to go get the part, and then go to a friend's garage, and do all the work.I am going to make the entire trip at 35 MPH. LOLFunny enough, when I made the trip yesterday, my gut feeling was that it was ok, up to about 45 or so. Kind of nice to have your gut feeling corroborated.=0)I may diconnect that actuator before I leave, as well. So the front half axles will not be engaged.I have work to do before I leave, and the parts store is not open forever, so I have to get moving. I'll let you know the day's results, later.Thanks everyone.
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Mark,Thought I'd explain a bit here...The difference between the vacum switch and a modulator is:A modulator uses vacum to make a mechanical change in the tranny or transfer case.For the vacum switch: A mechanical change occurs in the tranfer case, that opens the vacum switch and allows the vacum through.They are opposites.=0)
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I saw that. So I take it that the vacuum switch is now working correctly, but there is another problem. If you have a vacuum pump (I don't either) you could try to get the actuator to move that way. On the motor-maybe it isn't getting voltage due to a bad relay etc.
Well, the vacum switch is replaced. Whether it is working or not... ;o) You get the occasional lemon, no matter what the product is.I -had- a vacum pump, until I lent it out, and it came back broken. ("It was broken when I borrowed it." Uh-huh. Riiiight... I loan out broken tools all the time. Uh-huh.)I'm going to remove the battery and tray, and get that controller out of there. Then disconnect the controller, and operate that cable by hand a few times.I don't know exactly how I'll test to see if voltage is getting to the motor. It almost takes a second person, pushing the button. Gotta push the button, and test for voltage as the button is pressed. I'll extend the leads or something.Taking my laptop, because I could be there half the night. Besides having to sit there for a few hours to let it cool off this time. Gotta fill my BT addiction...
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Jeff, the clutches in the TC, may be shot. Mine are in full lock, and as it was explained to me by a GM techie, the wrong oil in there, ( get this, from the factory) can do that. I don't think draining the TC is it, I think I heard, it takes a rebuild.
Hang in there, we'll figgure it out with ya.
There's clutches in the transfer case ?All I see is a big gear and chain like the timing chain/gear setup.I suppose they are in the other end of the case.Sitting in the garage waiting for it to cool off right now.
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Yup. The TC has a series of clutches, all bathed in oil. That oil..is the problem I'd bet. Skanky or water flooded, or wrong vis. will FU the grabbage of the centrifical discs...you do know you have a better chance of the engage/dis-engage under load/power...right?
Bad news is, you have a full time fwd, good news is, you don't need to swap out the TC.
You will not hurt the front box! As long as it is full ( a ratchett stub fits the filler/check oil plug) of 90w oil. The tranfer case wants ATF ( I think)...'93? Yeah. The ATF juice is not Dextron and your TC is locked..yer chasing the wrong bear up the wrong tree.
Flush the TC, yes it takes a suction device, similar to a oil transfer pump,re-hyrate with what the manual says, I think it is Dextron, ONLY. Drive a an houe and, yes, repeat.
The carriage assembly is fouled, and the clutch plates are slipping past dis-engage.
Or, ya lunched the whole TC, by fiddling with the vacuume and starved the throw out sensor, and now ya gotta make a choice..4wd or 2wd, for ever.
have you tried putting it in 2WD and backing up, just running it on dry pavement in 2WD in case something is overtorqued from being in 4WD.
bobl Volo, non valeo
Baloney detecter WFR
"But when you're a kibbutzer and have no responsibility to decide the facts and apply the law, you can reach any conclusion you want because it doesn't matter." SHG
Bob, it won't go into 2wd. That's the reason for the thread in the first place.=0)
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What I know about mechanics isn't much, but let me throw something out here.When Mary got her Isusu bathed in salt water, certain things didn't work quite as smoothly anymore.So after spending a whole summer in 2WD, when we finally tried 4WD that next winter, it would go in but not come out again. I theorized that some rust was making things hard to work.But if I shifted out of 4WD, then put it in reverse and backed up to a speed of about 20MPH and hit the brakes hard, it would pop loose and go back to 2WD again.I mentioned this to my mechanic, he said "Yeah, a lot of those older 4x4s are that way after awhile. Sometimes all you gotta do is pull the axle and clean and grease it up"I realize this doesn't fit all of your symptoms, and you have a different species of animal, but it might be a help to ponder.Now that I've told you more than I know, I'll shut up and let somebody else spin their wheels
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First, I want to say thank you to everyone who has answered here. I do appreciate the help. (Regardless of how I come across sometimes. LOL)Piffin, your advice/experience, and that of Bobl roughly correlate to the advice given by a service mechanic to someone else who had a problem similar to this.He said..Put the tranny in nuetral. (With the car running.)Put it in 4hi.Switch to 4lo.Switch to 4lo again.Switch to 4hi.(All the above is while it is in idle, and nuetral. No shifting or anything in between.)Back up a few feet.It should now switch to 2wd.~~~That is the plan.First I'll get the flash codes.I'll do that switch and backup thing next. Although I am going to take your advice right away, and give it a bit of speed then hit the brakes.If that doesn't work, I'll disconnect the battery for at least half an hour.If that doesn't work, I'll disconnect the actuator before I drive it on the highway to where I will work on the rest. That should at least put the front half-axles in nuetral.~~~Thanks again to everyone.=0)Now I gotta go find a new vacum switch, because that definately needs replaced.
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If the vac line has fluid...it's ATF from the TC...replace the switch on the TC. If you ignore it, you'll wreck the HVAC controls in the dash. The oil destroys the diaphram for the rotary switch in the HVAC control head as well as the front axle servo. When you remove the switch you'll most likely find the ball stuck in.
Now, are certain the TC is stuck in 4x4? The stuck switch can cause a non release of the servo which can make the truck feel like it's stuck in 4x4 when turning. The front shaft eddie was talking about is the front shaft from the TC, not the front half shafts you mentioned. Problem is to remove that shaft, you'll have to drop the front exh pipe and the trans crossmember to get it out.
Next Q...when you press the dash switch does the 2wd light flash or does it stay on steady or what happens? That alone can answer alot. The system is capable of flahing codes by jumping the DLC connector under the dash. I'll have to check what terminals you jump...I forgot ;-)
Worse case...the encoder motor on the side of the TC is spent. Common problem with that system. But don't just guess by swapping parts. Diag is critical with this problem.
Gotta run for now, but I'll be back when I can
edit...don't forget to top off the TC with ATF or you'll burn it up!!
I've upped my standards...now up yours
Edited 6/12/2007 11:23 am ET by caveman
Whuf.Let's just say that I am glad I decided to take this seriously right away.Ok, here's the plan so far...From all that I have read, it is possible for something in that switch/shift motor combo to become screwed up in such a way that resetting the computer can fix it.So my first action will be to disconnect the battery for half an hour, and then reconnect it. If that does not fix the problem, then the truck is going to have to be driven a few miles more, to get to a place where I can do the work of removing the shift motor from the TC, and putting the TC into nuetral. That will put it back into 2wd, and will prevent further damage to the 4wd system until I can fix it correctly.~~~Now that I have read this, I will also disconnect the lines from that vacum switch.I'll probably trace both lines up to the front, remove them from where they are connected up there... And cap the ports they come off of, with either a rubber cap, or a short piece of NEW vacum hose that is plugged with a golf tee or something.Sounds to me like the vacum switch has to be replaced, regardless of whatever else I do.~~~Well, I -was- certain the front differential is being driven. And from there, the front halfshafts. So, yes, I -was- pretty certain it is stuck in 4wd. LOL ;O)But after reading your explanation here, I am wondering if that is the case.I guess the best thing to do will be to get at the actuator in the front, and release that cable, and see what happens.The easiest way to do that will be to pull the vacum line from the actuator and release that vacum.Then pay very close attention to whether the TC still seems to be in gear or not, as I drive to where I can do further work.If all is 'fixed' at that point, then I need to replace that vacum switch, and the vacum lines. I am thinking of replacing the vacum lines with copper or steel tubing, and only 8 or 10 inch pieces of rubber line at the ends. This will eliminate long soft lines that can be sucked closed, (They are extremely soft right now. Probably from that fluid.), and/or burn by coming in contact with the exhaust. Good idea ?If the TC is still in gear, and does not come out of gear after resetting the computer and the other things I will do... Then I have to delve further in, and find out whether it is the controller, or the shift motor.Does this make sense so far ?~~~I had already guessed I was going to have to drop the exhaust and trans crossmember,(*GROAN*), to get to the vacum switch.Do I have to do the same, to get to the shift motor ? Hey, you can't blame a guy for asking and hoping. LOL~~~The toggle switch has two lights. The top light is green. That is labeled hi.The bottom light is amber. That is labeled lo.When you push the top of the switch, it goes into 4wd hi. When you push the top of the switch while it is in 4wd hi, it is supposed to go back into 2wd. And it always has before now.When you push the bottom, it goes into 4 lo. To get out of 4lo, you push the top of the switch, and it goes into 4hi, then you push the top again to get back to 2wd.The green light has always flashed. It flashes every time you push the switch. Even when you put it in lo, by pushing the amber/lower part of the switch. Push the amber, you go directly into 4lo. The green light flashes several times and the amber light comes on and stays on.Push the green, the green flashes several times, then stays on to let you know you are in 4hi. Push the green again, and it flashes several times, then goes out to let you know you are out of 4wd.Right now what is happening, is that you can get into either hi or lo. The green light flashes as always. But when you try to go from 4hi, to 2wd, the green light flashes, you hear the appropriate clicks from behind the kick panel, and on the TC... and the light stays on. ~~~I am supposed to jumper the a and b terminals.I'll probably go out there and do that in a bit, and write down the codes I get.I'll top off the TC and the front diff, both. Probably even top off the rear diff while I am at it.Man, I really didn't need this hassle right now. But then when is it ever a good time ? LOL
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Let us count your blessings...1> you have a truck that runs
2> you will not be laying in a puddle with a freezing north wind up your butt
3> you will be glad when it is all done
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ROFLMFAO !!BazACTly !!!Plus, if the vacum switch is the only thing that needs replaced, (aside from the hoses), it looks to be a cheaper repair than I feared. (See... worrying DOES work ! LOL)Just going to be a lot of work.I'm up to it !=0)
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Re: counting one's blessings...I have a saying, The poorest of people are those who have neither options, nor opportunities. And I just plain ain't that poor !;o)
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Sounds like you got a plan and your on the right track. As for replacing the vac lines with tubing...I'm not sure I'd go through the trouble. Sure it will be better than OEM, but as long as you route the hoses above the trans, you'll be fine. Other than the switch failure causing oil to get sucked through the hoses, the only other problem to be concerned about is the exh cooking them...and that's only cuz some hack R&R'd the trans and didn't route them correctly.
No need to drop the exh or crossmember to access the vac switch or encoder motor. Both can be replaced without removing anything else. Sure...it sux for access, but as you already know...so does everything else on that truck. :0) EVERYTHINGS shoe horned into place. Just make sure the engine is cold so you can stuff your arms up above the TC with out toasting them
I was wrong on the flash code capabilities. Yours is the 1st design system and diag is done with a volt meter. All you can read on your truck is engine & trans faults by jumping A to B. The flash code system for the T truck 4x4 didn't start until 95 1/2 model year, which you would jump A to J for TC codes.
One last point worth memtioning is if you want to be sure the TC is not in 4x4, with the front axle disengaged(pull the vac line to the servo) see if you can spin the front drive shaft(not the 1/2 shafts) with your hand...you should be able to.
Hope this helps...post back if you need more assistance I've upped my standards...now up yours
LOL, " EVERYTHINGS shoe horned into place."Yep, they started with a nice small V-6 getting good mileage, then managed to find a way to cram the bigger Vortec in there by jamming everything else aside and making it almost impossible to change oil or two of the plugs
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True, but that POS egg beater 2.8 the 4.3 replaced was about as worthless as t**s on a toad.
A Chevette diesel with the AC on max had more get up and go!! I've upped my standards...now up yours
well now, I passed every other small truck on the road when I had mine - loaded with tools!
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Downhill or drafting someone ;0) I've upped my standards...now up yours
Naw, they were headed the opposite direction. Piffin was a bit late to work that day. ;-)"Poor is not the person who has too little, but the person who craves more."...Seneca
Cavedood,A few questions, if it isn't a bother...How do I diagnose the electric side of this with a volt meter ? Am I just looking for voltage, and/or ground ?I have resolved myself to take the truck back over to the garage, put it up as high as I can get it, (clearance for my fat self.), and do whatever it takes to either fix the problem for real, or at least get it shifted into 2wd and left there until I can afford the parts.I know there is a kit to replace the actuator up front, with a cable quite similar to a choke cable.Do you know if there is a kit available to replace the shift motor with something similar ? I don't want to go to all the trouble and expense of putting in the factory manual shifter and all that. (That would be even more money and time than just buying all the parts for this system, new, and replacing them.) I am hoping for a simple cable system that replaces the motor on that shifter.~~~Here are my thoughts...I think there is a possibility of a problem inside the front differential. Caused by all that time locked in, and suddenly now, unlocked.Somthing is sticky. Something is broken. Whatever. I'll have to manually operate it a few times and see if that fixes it.There is also a possibility of a problem with the electric switch on the diff that tells the system whether it is engaged or not. And the further possibility that a faulty switch there could be causing the system to not want to shift out of 4wd.As far as the TC, and actually shifting into/out of 4wd/2wd, is concerned.Possible problem with the controller that controls the shifter.Possible problem with the shifter.Possible problem with something sticky/broken in the TC.~~~I just hope that I don't end up having to R&R the diff and the TC...
Fight fire with water.
i have had a jimmy for many years and there was a switch an the transfer case i would change pow back i 2 wheel drive .now i own a mazda much more camplicated system.i miss those jimmy days
wait till winter ...
and find an icy road.
or ... drive now and find a real mud bog.
far from home as possible.
check for cell reception ... if U have any ... this won't work.
gotta be a dead zone.
now ... approach mud/snow as per the norm ...
drive in halfway in 4WD ...
turn truck off ...
guaranteed when U restart ... you'll only have 2WD!
not really a fix, per say ...
more of a realignment of problems ...
pretty much all my vehicles have "fixed" themselves this way ...
same with actually having a bit of money left over in yer wallet ..
wife's car smelled mine ...
so it's off the the shop on Thurs ..
bet what ever that noise is ... costs a dollar more than I had set aside ...
Jeff
Jeff
Buck Construction
Artistry In Carpentry
Pittsburgh Pa
ROFLMFAO !!!!Perfect. And I'll bet it would work !;o)~~~Well, I've been to town and back already.You are right even about the money. I had about thirty dollars left, and it cost all of that. Guess I'm lucky it didn't cost 50.=0)~~~I discovered something really wild...This vacum switch has obviously been a problem since before I got the truck.They had let the vacum lines be burned in half and didn't do anything about it. That said, they probably had better gas mileage than I have had so far... LOLOk, here's the poop.I tried all the tricks everyone could suggest. Nothing worked. It was still in 4wd.So I decided, as you know, to go to town at 35MPH and get the part.~~~I mostly coasted my way, most of the way out of MIR. On the way out, there is a big turnout area under the high voltage towers, where people park, and then go down to the river with their kayaks and such.I pulled over there, to do the mechanical surgery I had already decided on. I cut the vacum line going to the actuator that is under the battery. Big time vacum was in the line. I whittled a plug out of a piece of wood I found on the ground, and plugged that line, so there would be no vacum leak.Then I headed back out on the road.It immediately drove and steered like it was out of 4wd. Back in 2wd.Got out to the highway.....Un freaking believable.It sounded, felt and drove like it was in 2wd.Only it was BETTER !!!!Never a whif of gear lube. Now get this...The overdrive slippage is gone. Gone.That slippage has always been there, and had gotten worse.I coasted at 1100 to 1700 RPMs 98 percent of the trip. Even at 60 mph.That is compared to the 1800 to 2500 RPMs that it normally runs at.Used to be, you could take your foot off the brake, and gas, and let it coast, it would slow down quickly. Like driving with the brakes on.Now. It coasts. Period. The only slowdown is natural slowdown.It even sounds quieter.That actuator has obviously ALWAYS had vacum, and has always been activated.So, while I was not in 4wd, the front differential was STILL in gear.When all is said and done on this project, I should see better gas mileage, at the very least.Now, if repairing this part of the system, still doesn't get the 4wd to disengage at the TC, I'll just have to leave the vacum assembly actuator disengaged until I can afford to replace the other parts.Going down the highway, the TC may well be engaged. And it may even be spinning the gears inside the front differential. But there is no load at all on the gears. Everything is free spinning in it's gear lube bath. No damage is being done. Well, no more than normal. And, in fact, much less wear/damage is being done to the differential.If worse comes to worse....I'll make up my own "posi-lok" cable system. And then check the fluid level in the TC and differential on a regular basis.There is an aftermarket cable system that replaces the vacum assembly.http://www.4x4posi-lok.com/app_chevy-s.htmlI CAN make that cable system up, my own self.If I have to, I will. With that, I can engage the front differential from the driver's seat, by pulling on the cable. Disengage by pushing it back in.Of course, even easier than that, would be to add a bit of vacum hose, and put in some small valve I can open and close to activate and deactivate the actuator.I could run that inside as well. But it would be just as well to leave that under the hood. It's not like I need to switch in and out of 4wd 'on the fly'...Anyway, bottom line, in a way, it's good that this happened.Because this has been a problem for the entire time I have had the truck. The vacum problem has been robbing me of gas mileage, and causing undue wear on the front differential and axle half-shafts.Now I'll spend the next couple days trying to get the truck set in a safe place, and getting the repair work done.Once again, thanks to everyone.=0)
Fight fire with water.
Cool...sounds like your in biz again. I'd be WTB the TC and encoder motor are fine and the whole problem was just the frt axle staying engaged.
After you replace the vac switch, be sure to install the vac hose connector correctly. It is keyed with a pin...look on the switch and then the connector, so just line it up . If you fudge it up, you might end up with the same condition again or no 4x4 at all I've upped my standards...now up yours
Ok, I finally have all the preliminaries out of the way. (Had other errands to run, got an emergency call and had to make a trip for that, etc.) Now I am ready to go get the job done.I am taking time to get a bite to eat right now, then I'll be heading out. Going to take it to a friend's house and do the swap of the vacum switch there. He has a garage, and a nice flat safe driveway.;o)As I see this, I can divide the one system into two systems. The electronic half, and the vacum half.The electronic controls the TC part of the system, and the vacum system controls the diff part of the system.The only link between the two is that little rounded rod thingy that sticks out the back of the vacum switch and into the TC.Is there a microswitch or something similar inside there, that provides feedback to the electronic/TC side of the system ?If that rod is not serving a dual pupose there, (Feedback for the TC side, plus mechanically opening the vacum switch.)... Then it is still entirely possible that the electronic/TC side of the system has kakked.When you push the toggle, it activates the relay in the kickpanel, which in turn activates the shift mechanism. It is that part of the system that is refusing to work. While it will switch from 4 wheel high to 4 wheel low, and back again... It will not go back out of 4wd. It will not switch into 2wd.So right now, the TC is still in 4wd. But the front differential is disengaged. So the diff and TC are now freewheeling.I guess I'll know in a couple hours whether the vac switch makes the difference in the TC side of the system.There is no doubt the vacum switch needs replaced. I just hope that that is all that needs replaced.~~~"and that's only cuz some hack R&R'd the trans and didn't route them correctly."Exactly.Some hack did that back when the previous people owned the vehicle. Then the hoses dropped down against the exhaust and burned in half. Those people never figured it out. They just lived without 4wd.When I got the truck, I had the vacum lines reconnected. The shop STILL did a hack job of it. They didn't even bother replacing the lines, they just stuck a plastic connector between them. The lines are so soft, it's a wonder they don't get sucked closed. And they are still badly routed.I plan to cut the lines coming from the vacum switch connector, fairly long. Then cut a couple pieces of copper tubing, (Already have it, so might as well make use of it.), and route them above the TC, to a place that is better accessible. I'll wire tie the copper to solid mounts.Then new rubber hoses on the top end. I can't replace the soft hoses that are already there on the vacum side unless I buy a new connector.I have fat hands and arms. I may have to take things apart anyway, to reach into there. We'll see, once I get it jacked up and get the wheel off on that side...Gonna be pizzed if I find that my hands and arms are fat enough that I have to do something even more drastic than renmove the eshaust and the tranny crossmember.
Fight fire with water.
Luka, old buddy, please don't drive that truck on the highway in FWD. By every thing that I understand, it is dangerous. That vibration is telling you something.
I don't know from Jimmies. If my F250 stuck in FWD in the transfwer case I just unlock the front hubs. Then the front drive isn't fighting the rear drive.
I hope that some one who know Jimmies logs on because I know you've got to get to places.
BJ
BeeJ, how are ya ? Been a while since I've seen you.=0)I'll never have it on the highway with the front wheels engaged again. (Well, unless there is three feet of snow on the ground and I am going 20 MPH or less. LOL Even then, I am not likely to be in 4wd on the highway.)Figured out how to disengage the front differential, no matter what. That gives the same result as you unlocking your front hubs. We all have to learn whatever we learn, somehow, sometime. I've just had my lessons in 4wd. I just hope my lessons didn't cost too much damage in the 4wd system. ;o)=0)
Fight fire with water.
this probably does not apply to your situation, but still of interest -
my 4runner was stuck in 4wd merely because I had put on the spare which had much more tread, making it a different size than all the others, which somehow confuses the genie under there....
ROFLOL
4wd genies, I'm gonna have to remember that.
=0)
If I have figured all this out correctly, the vacum switch gives a sort of feedback to the shift motor. (Through the innerds of the TC.)
Specifically, there is a rod inside the TC that pushes against the back of the vacum switch, when the shift motor shifts the TC from 2wd to 4wd. That opens the switch so vacum can flow through to the actuator. The actuator then pulls on the cable, and engages the front differential.
The vacum switch has a ball looking thing at it's tail end that pushes back, when the shift motor shifts the TC from 4wd back to 2wd. This allows the switch to close again, releasing the vacum feed to the actuator, and the actuator disengages the differential again.
The current vacum switch obviously does not push back.
That lack of 'feedback' from the vacum switch could well be what is upsetting the controller/shift motor combo and keeping them from shifting back out of 4wd.
At least, that is what I am hoping is going to turn out to be the case.
=0)
Here's a pic of the culprit. This is the new one.
View Image
I'm thinking that over time, the spring inside the vacum switch has gotten weaker and weaker, and just finally gave up the ghost completely. No longer has enough oomph to push that rod back into the transfer case, at all. While it has already been broken for a long time as far as the vacum leaking through the switch is concerned... There still might have been enough oomph in that spring up to now, to get the shift motor and controller to do their jobs.
OK man, where are you eating that has TABLECLOTHES that are clean, huh?
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
That's a paper towel.;o)
Fight fire with water.
LOL, I knew I recognized that pattern! I eat of them regularly.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
An exercise in futility and frustration...
I got the switch exchanged.
I -was- able to reach up in there. Still burned my hand many times. I couldn't wait hours for it to cool off. The exhaust was cool to the touch, but the TC was still burning hot.
Did not fix the problem. It still won't come out of 4wd.
And the front differential locked in again.
Only this time, when I removed the vacum line... it stayed locked in.
To add insult to injury, when I got home, the dang truck and hillside decided that today was the best day ever, to cooperate and make for a carnival ride.
The truck slipped and slid all over the place. It was like I was driving on ice. It just kept sliding and sliding, I am gripping the steering wheel so tight it's a wonder I didn't leave grooves in it, and have the brake pedal pressed to the floor, and it just keeps right on going... and I ended up in the ditch.
View Image
No, that wheel is not resting on that rock. That rock is a good 8 inches away from the wheel. That wheel is hanging in mid air.
I'll make this post and then get back out there and try to winch it back out of the ditch. If I am successful, then later when the truck has cooled down, I'll go out and remove the battery and battery tray so I can get at that actuator under there. I'll remove the cable and operate the cable by hand. Hopefully that will at least get the diff loose again...
Looks like I am going to have to buy the more expensive parts. That means the truck sits until I can afford it.
I may drive it if I can get the diff loose again.
Fight fire with water.
Ok it's out of the ditch.I think what happened is that I had it in 4 low, and the front differential chose that moment to finally let go. The rear wheels were churning away, (overpowering the brakes.), and the front ones were just sliding. Had they been in gear, they would have done what I expected them to, and I would have driven out of the slide.~~~I spent half an hour cranking with a come-along, trying to pull it up out of the ditch.Then someone with a 4wd pickup stopped. We got my chain out, I turned the wheels to face toward the passenger side, (to the left in the pic)... He pulled downhill, (which is to the right in the pic), with the chain hooked to my tow bar in the back. The object was that if he pulled downhill, he had the advantage of both gravity, and his 4wd. And my turning the wheels what seemed like the wrong direction, meant that as soon as my front wheels could grip anything, they would be driving the front end away from the ditch. Even though the back end had to go the same direction. Well, -I- thought it would work, anyway.And it did.;o)Amazed the other guy by how easily it worked. He said he didn't even have to give it gas. I've done this enough times now, that I wsn't surprised.=0)When it was hung up there, I should have gone around back and took a pic as well. But you probably would not have been able to see it as well in the back... The back, passenger side wheel was dangling in the air, even more than the driver's side front was.I was stuck on the tow bar, back there.Enough for today. I've got to settle down and get rid of the stress, or I'm going to go agoraphobic and prone to panic and anxiety attacks.
I'll get back to worrying about what the real problem with the 4wd is, later...
Fight fire with water.
Good luck. Looks like a hairy ride there.
I think I puckered so badly that I made a crease in the seat.When the towbar hit back there, it was a sickening sound. I thought something broke.
Fight fire with water.
just as a note if you have a 4wd and dont use it much remember to put it in every so ofton to lube everything up, this will help going in and out easyer
Well, I did all I could yesterday. Couldn't get it to shift out of 4wd.
Finally ended up just taking the forward driveshaft off. And disengaged the front diff.
It'll have to stay that way until I can afford to buy the rest of the parts.
If replacing the parts that I can do so without removing the diff and TC doesn't fix it, I may just end up taking it to a shop.
Luka,
I have not read all 60 of the responses so forgive me if this is a repeat. First of all, it would probably be worth $25 to go to http://www.alldatadiy.com/ and buy a one year subscription for your truck. Then you will have all of the factory service information. You might save the $25 just not having to buy un-needed parts.
That being said, I am pretty sure Warn makes a manual cable setup for at least the front axle part of the system. It does away with the actuator motor and you just have a lever to pull. These trucks are all known for this type of problem. I dont know if they have a similar system for the transfer case. I have heard that a lot of times the only problem with the TC is a switch ?
I am glad I stuck with the fully manual system on my 99 Tahoe :) By the way ... the back up to disengage deal was only on the earlier trucks with the straight front axles and automatic locking hubs. None of the IFS trucks use that system.
Hopt this helps,
Bill Koustenis
Advanced Automotive Machine
Waldorf Md
I get my fwd answers from pirate4x4.com go look in the chevy section, but remember they are not nice people. they make jlc look like choir boys
That place is worthless. Maybe ok for browsing, but worthless for finding any really helpful info in any reasonable amount of time.The only search function that I can find is for the FAQ.I put a simple search in and it found nothing.I kept deleting words from my search until I was down to just one word. "Shift".It found no matches for the word shift.The word "shift" does not appear ANYWHERE in the entire FAQ for a 4x4 site ?Yeesh. Give me a break.
Fight fire with water.
Bill,Thank you very much.Does this site give you more info than a haynes and/or chiltons ?Both have been more than worthless for this problem.Warn may make that cable setup. You can also get it in a setup called "4x4 Posi-Lok".http://www.4x4posi-lok.com/app_chevy-s.htmlBefore I even knew anyone had a kit for that, I was already putting exactly the same cable system together in my head. I still may do it. Using an old choke cable, or hood release cable, or whatever...Only thing that kept me from building one yesterday is that these people claim there is a switch in the kit, for some electric setup at the front diff. I have no idea what that would be.After my dinking around yesterday, I became convinced there is a good chance that something has been screwed up in the diff, by the way it was locked on for so long.I am not positive, but I think it may not be letting go, completely.I did test the actuator and it does hold a vacum very well. So it was definately holding the front diff in locked/engaged mode for at least as long as I have owned the truck.Yup, back up to disengage did nothing. LOL Nor was the liquic low in the tranny, the TC, OR the front diff. Everything seems to be ok. It's just that the TC will not shift out of 4wd. And I would swear the controller which is behind the kickpanel is doing the right stuff. I am kind of left with either the shoft motor mounted to the TC is bad, Or there is something wrson inside the TC itself that is preventing the shift.I would give my left noogie for a nice simple cable system to replace that shifter motor at the TC. Yeah, I know I could retrofit the entire manual shift system, but that would cost as much time, and even more trouble than fixing what I have.I CAN manufacture the cable system to replace the actuator. I wish it were as simple to do the shifter as well.Of course, that shifter motor assembly really doesn't look like it is very beefy. Makes me think it doesn't REALLY take gorilla strength to shift that TC. If so, then if I could get a clear picture of all the pertinant prts, I just might be able to build something simple to replace that as well.It really seems to me like I should be able to devise something to take place of ONLY the motor on that shift mechanism. Leave the rest to operate as it should...I think it was Caveman that said the 4wd system on this truck is separate from the computer systems. I do believe he is correct. So I would only have to disconnect the extraneous stuff, and put my own two manual cables on...If I had a cable to replace the actuator, that's half the solution. The other half would involve a simple, small lever, mounted up under the dash. In fact there is a sort of "storage shelf" incorporated into the underdash of this truck, that would be a perfect place to mount the mechanism.This post has wandered, so I will ask the most important question again... Does that website actually have better information than I can get from a chilton's or haynes manual ? If they have detailed vacum diagrams and detailed electrical diagrams for the different models, years, etc... That alone would be worth the price.Haynes has only some basic wiring, (not often very useful if you run into real world problems.) and no vacum. Chiltons has neither, that I have seen.
Fight fire with water.
I got the factory manuel for the 86. the front axle here is called a T truck front axle and on the right side of the aluminum center there a cable attach to a sleeve inside the tube that disconnects the front end. cant find the other book on the transfer section
An 86 is a totally different animal.=0)Although, I am going to be looking at the 4wd system on my 83 blue blazer whenever I get it back on the road. That ones all manual shift.
Fight fire with water.
Is there a vent tube on your frnt diff?
I "think" that is different differential than mine...my diff is not vented, the previous one was...I'd be curious as to why they do/did that.
Your problem is still in the TC I bet, but I recall some models had ele feed back to the TC ( or vacuume) and if the vent tube is gobbered up with wasps or mud, it will send the wrong value to the TC, for engage/disengage. When a frnt wheel has grabbage, or slippage..it tells the TC to do something else to apply torque to the "solid" wheels.
I'm no expert, just looking at options for ya.
Awe crap, I should shut up..I just know enoughto be dangerous.
"Awe crap, I should shut up..I just know enoughto be dangerous."I figured that out a couple posts ago.;o)=0)
Fight fire with water.
when you figure it out, let me know what it was
Loose nut behind the steering wheel.
Fight fire with water.
When you disconnected the front driveshaft, did it spin freely? Did you drive the truck and hear it banging around?
The front axle cable and slider may just be hanging up due to being stuck engaged for so long. When you pulled the vac hose to the front axle servo, did the servo remain sucked in? If so, that just proves something is stuck. Ther's no elec in the frt axle, it's all mechanical engagement.
Tell you what, let me hunt down a manual for that year. We donated all our old ones to a local Tech school and everything we have now is over the web. Only good for 97 and up as far as GM goes. We also have Mitchel? or whatever, but I have seen some bogus info from them.
For now, answer me this...is the frt axle still staying engaged with no vac to the servo? Does the frt driveshaft spin freely when in 2wd?
Also...just for the he!! of it, take a jumper from A to J and count the number of times the switch lights flash...if it does...just like you did when you jumped A to B for engine codes. BUT, BE SURE to install the jumper BEFORE you turn on the key. The literature I read said it wasn't functional for that year, but I have my doubts now.
I've upped my standards...now up yours
After I took the short driveshaft out, the front diff yoke spun freely.The yoke in the TC does not. The TC is still engaged in 4wd, and will not shift to 2wd even now.I do think there is some possibility of stickiness in the front diff. But it's also possible that that stickiness has gone already. As evidenced by the way the yoke spins freely.I put vacum on the hose leading to the actuator, then held the vacum in the line, and as long as the vacum was there, the actuator stayed closed, and had the cable pulled back. Pull the vac, the actuator lets go on the cable. The only thing I am not sure of there, is I wonder if the cable is not going completely back into place. But it is obviously going back far enough to release the diff gears.According to what I have read and been told so far, there is a switch in the front diff that tells the rest of the system when the front diff is engaged, and the vehicle is in 4wd.But as far as I can tell, you are the correct one. Because the system Still thinks it is in 4wd, when only the TC is actually in 4wd and everything else is disconnected."For now, answer me this...is the frt axle still staying engaged with no vac to the servo? Does the frt driveshaft spin freely when in 2wd?"No.The front driveshaft will not spin freely, because the TC is in 4wd and will not shift into 2wd. But with the front driveshaft removed, the yoke on the diff spins freely, and the yoke on the TV does not.The fact that the TC will not shift into 2wd has been the problem from the beginning. That is what I am trying to figure out. Why will the TC not shift out of 4wd ?The deal with the front diff only came into things because I discovered that it had been engaged for a long time. That has nothing to do with the original problem.At this stage, I am pretty much convinced the front diff and the vac actuator work as intended.I also think the controller behind the kick panel is working.It comes down to that shift motor on the TC, and the TC istelf.When I can afford the part, I will replace that shifter. If that does not fix the problem, then the problem is probably inside the TC.At that point I have to decide whether to take it to a shop, or R&R the entire TC, myself.I'll try the a-j terminals sometime today and see what happens.I may not even have a j terminal. I noticed when I jumped a-b, that there were not very many terminals at all. Big plug. But all empty except maybe 4 or 5 terminals...
Fight fire with water.
OK...I see where your coming from now. You had 2 different problems and that was cause for confusion. But as it looks now, most likely the encoder motor on the TC is NFG. I haven't located a service manual yet, but give me some time...I'm sure I will. There are several sources I can get one from if they still have it.
Meanwhile I'd still like to know if you can flash code it. The terminal layout for the DLC (connector under the dash) is........
F E D C B A
G H J K L M
There are only 4 codes, so try that and let me know.
The frt axle only uses a elec switch for manual 4x4 shift setups. All it does is provide a signal to illuminate the axle on the floor console showing it's engaged. On the elec models(yours) it's not used. Unless your frt axle has been swapped, there shouldn't even be one. I've upped my standards...now up yours
I have come to the same conclusion.Either the shifter motor on the TC is shot, or there is something wrong inside the TC.I'll replace the shifter motor at my earliest convenience.No flash at all when a and j are jumpered.
Fight fire with water.
ok, no flash could mean no flash code capabilities even though I still think it is.
On a brighter note...I found the correct manual. It's about an hour away, so either Mon or Tues one of our gophers will pick it up or I'll go get it.
btw...you did jump the terminals first BEFORE turning the key on right? just want to be sure. Also you will be watching the 4x4 switch light for the flashing of codes I've upped my standards...now up yours
I had it jumpered before I turned on the ignition.Tried half a dozen times, just to be sure.Although, I was watching the dash, not the 4x switch lights. I'll do it again today and watch those lights instead.Thank you.=0)
A friend is a person that knows everything about you and still likes you.
If there are any codes flashing pay close attention to how many flashes the light switch has...if only 1 code is set, it will repeatedly flash that code with a 3 sec delay between. If there are multiple codes, each code will flash once then it will repeat all of them again.
For example...in case I'm not clear as mud ;)...say it had 2 codes. Codes 2 & 3. The sequence will be----blink, blink for #2 and then 3 sec pause and then blink, blink, blink for #3, then repeats itself If only one code is set say #2...it will be blink, blink (3 sec) blink, blink (3 sec) blink, blink etc etc
This is different than the SES/CEL in the dash that flashes each code 3 times before continuing with the next one. I've upped my standards...now up yours
No flashing lights of any kind, anywhere.Never mind about the manual. (I can't remember asking for it. If I gave you that impression, I'm sorry. I hope it hasn't cost you anything.) I can't afford to buy it. Nor the part.When I can afford the part, I'll replace it and see if that fixes the problem. That's about all I can do for now.I'm already better off, just having gotten the front diff unlocked, and taking the front driveshaft off. I can't swear I am getting better gas mileage, but it seems like it.I got the revs up to 2200 today, climbing a couple steep hills, and I noticed how strained that sounded. I'm already used to the lower revs. LOL 2200 used to be cruising revs...
A friend is a person that knows everything about you and still likes you.
Never mind about the manual. (I can't remember asking for it. If I gave you that impression, I'm sorry. I hope it hasn't cost you anything.) I can't afford to buy it. Nor the part.
Sorry but yur skrude dude...I bought it already so you own it now. I'll send Bruno by to collect the payment.
Blood---Bones or---Bucks...yur choice. ;)
Seriously ya meatball {GD&R} no ones talking about buying anything. I'm borrowing the manual from another dealer since ours is history. The only info I have right now is genaric. It's either incomplete or incorrect. GM had several versions of that system including different TC's. Better to work with the correct info than shoot from the hip. Trust me, I've been there before and it can bite you.
There's no cost involved in me borrowing the manual. So if you don't want me to bother getting it, let me know. Just remember--if you buiy a part you don't need...ie the encoder motor...you now have a spare :0)
I've upped my standards...now up yours
Spare parts are good.Having spare parts because you bought expensive parts that you didn't need... Well...Agreed about the info. The right manual is invaluable.Biggest problem here is going to be when you start asking me to crawl under there and get part numbers, etc. LOL That is not something that will be readily done.When you get the manual, can you give me any idea what could go wrong inside the transfer case that would disallow shifting into 2wd, but still allow 4wd hi and lo, and still actually work in 4wd... ???If that is not possible, then pretty much the only thing left to deal with is the shifter motor. Well, except for the controller. But it seems to me that the controller is trying to make the shifter shift. It just won't actually shift.
A friend is a person that knows everything about you and still likes you.
Drive it into that ditch again
You'll have plenty of room to crawl under there
<G>
car-parts.com
Cool !There are many parts I wouldn't mind ordering that way.But I have a policy of not buying any electric/electronic parts from junkyards.Not even local parts yards. Let alone some yard off in SC or florida.=0)
A friend is a person that knows everything about you and still likes you.
I'll make a deal with you.I'll drive it into the ditch.You crawl under it.;o)
A friend is a person that knows everything about you and still likes you.
Finally...I should have the manual sometime today. Been a hectic week and all and one of the drivers already made the trip out that way, but he forgot the dang thing...he was at that dealer too:( Another driver is on his way as we speak and should return sometime this afternoon.
So as soon as I get it I'll pass on any info. Meanwhile the only thing that might be the cause internally would be a broken shift fork. If the planetary shid the bed you'd know it. I doubt you have an internal failure. Short of running out of oil and causing catastrophic damage these things are pretty bullet proof.
When you command 2wd from 4wd can you hear if the encoder activates?? You might want to try removing the encoder motor(sorry.. your gonna have to crawl under it :0) and manually shifting the TC. Use an adjustable wrench and rotate the stub fully counter clockwise. IIRC that should be 2wd. Also after you remove the encoder motor watch it and see if it rotates when you select the shift. See if it moves each time you press the switch.
Another thing to check is the fuses......... make sure all 3 are good!
1) motor feed--30A breaker (probably good since it shifts 4hi to 4lo)
2) memory feed--5A TCCM fuse.......maybe this fuse is dead and causing no codes??
3)system feed--15A radio fuse
So sit tight, I'll be in touch as soon as I have the manual. I'd like to know 110% about the flash code deal. I don't remember what kind of light show occurs with the switch when no codes are stored
I've upped my standards...now up yours
Edited 6/29/2007 2:30 pm ET by caveman
Can you give me the vin# for the truck or look at the RPO tag in the glove box. It is a list of all the option codes. The TC in your truck should be the New Process 231 or NP1 as listed on the glove box label I've upped my standards...now up yours
How many times have you gone through large repairs, ony to find out it was just the fuse ?I know. Me too. LOL *groan*I replaced every fuse with a brand new fuse a couple months ago. Just because...But I'll check the fuses the next time I am on pavement in a safe area, anyway. It still rains here like it was winter. I am not going to go crawling in sticky, slippery mud up to my haunches just to check the fuses.You know, you'd think that by now, they would have moved the fuses to a more easily accessible place...I'll get the vin and other stuff for you soon, though. Drop me an email, and I'll send it to you in email.~~~The rest of what you say, is pretty much as I hoped.~~~The only failure I was thinking about in the TC was maybe a broken tooth on a gear or something.~~~When I push the button, the switch in the kick panel clicks normally. (I can hear it.) Every time. 4hi, 4lo, 2wd, it always clicks the same. Difference is, it will go to 4hi or lo, but not 2wd.And yes, the motor down there on the TC is making noise. Although now that I think about it, I am not sure if the motor makes noise when you try to go to 2wd. I will check that out.You know, I really wish they had put some kind of positive switch in here to go to 2wd.You go to 4hi by pushing the green light. You go to 4lo by pushing the amber light. (Two lights on a rocker switch.) They flash all nice and pretty, and stay on if the shift was successful.To get back to 2wd, you push the green light. Again. (Twice again, if you were in 4lo.) When the green light flashes and goes out, you know you have shifted back to 2wd.But I wish they had put in a separate/third, switch/light. ~~~If they have exploded schematics of everything in there, that would be most helpful.~~~If I get this fixed, I am still considering replacing that vacum actuator with a manual cable, just so the same thing can't happen again with the front diff.~~~Thank you.
A friend is a person that knows everything about you and still likes you.
Waited till it hit 100 posts to say good to fix it now vs. driving for a year in 4WD on hard pavement and bre'king an axle <G?>
ROFLMAOI think that comes under the heading of counting my blessings.;o)
A friend is a person that knows everything about you and still likes you.
Oh, and you were right.I am actually beginning to like computers on cars now. ;o)
A friend is a person that knows everything about you and still likes you.
Mail call.... I've upped my standards...now up yours
Checked and replied.=0)
Yeh... That'll work.
Ok, Caveman has supplied me with some of the factory diagrams.
I am going to copy a small part of one of the diagrams and post it here...
View Image
If you look at the picture... Numbers 63 through 67 are the manual shift lever assembly. With #65 being the actual lever...
To back up just a step, I have already mentioned and linked to something called a "posi-lok" cable system that replaces the vacum actuator for the front differential shift. (I believe I can rig my own cable system, just like the aftermarket kit.)
Now, Look again at this picture. It looks to me like a cable system could be rigged to replace the electric shift motor, if one used this manual shift lever, instead.
I am hoping that it would be possible to do this without having to install the complete factory cable, console, etc...
Does anyone know if something aftermarket has been made for this as well ?
It's obviously just a simple forward-back operation, at that lever. Just like the vacum actuator on the front diff.
Seems it should be nearly as simple to rig up.
However, I have no idea what kind of torque it takes to move that lever...
Ideas ?
Yeh... That'll work.
68 thru 71 looks like the ball detent for that shifter, with 71 being the spring. If I'm right the spring strength determines how much torque ya gotta overcome.SamT
Caveman just told me of another problem.The shaft that comes out of the transfer case is threaded, for the manual shift.But on the one fitted with electric, the shaft is shorter and not threaded.At this point it looks like I just have to hope there is no problem inside the TC, and continue fixing the system the way it was put together in the first place.Still can't afford a replacement shift motor assembly, yet. But I should be able to, sometime in the next couple of months. Once I replace that, I'll check back in here and let you know what happens.
Yeh... That'll work.
Luka,
Alldata is the system that most automotive repair shops use. As far as I know it is all factory information, basically like having the factory manuals in front of you. I purchased a 1 year subscription for my 84 S-10 a few years ago and found everything I needed at the time. Another thing you might do is stop by a couple of the larger auto parts storesd in your area. I know a few years ago Advance Auto Parts used to have Alldata or Mitchell on Demand in thier stores for customers to use, its a thought.Bill Koustenis
Advanced Automotive Machine
Waldorf Md
MrBill MrBill !Thank you.I'll subscribe to that service.It's a long drive to the closest store I could get to, to make use of that.
Fight fire with water.
I remembered I have database access to auto repair manuals through my
library, let me know if there is anything specific you want and I'll see if I can
find it. For instance, your transfer case uses planetary gears, no clutches.
Edited 6/17/2007 9:56 am ET by MarkH
Chassis electrical 1993 drawings 1 and 2.
transfer case motor
engine electric for 2 different 4.3 1993 engines
Mark,Yer on the right track.I already have the gif image you posted. That one pic by itself was invaluable. I'll download the pdf's and read them later.Don't know why I hadn't thought of checking with my library, myself. I'll do that if I can't get it figured out with Bill's solution.FWIW, you see that little motor, marked 130... (You can see a guy's thumb up above it, so you can see a relative size for that motor.)My thinking is that there should be -some- way of replacing that with some kind of small lever, and a cable. -Without- having to install the complete factory manual shifter assembly.If that can be done, then together with the cable system for the vacum actuator, that should eliminate all the problems with the "automatic systems".
Fight fire with water.