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4x4 woes

1.9K views 18 replies 7 participants last post by  56Maynard  
#1 ·
yea, itsme again. with yetanother question about 4 wheel drive in my 85 s-10. it stopped working, and I havent a clue why... didnt make no sound, didnt shudder, nothin. it stopped engaging suddenly. it worked perfectly yesterday when I was pushing a car out of the way. and tday when i tried to engage it to go down a steep icy hill, it wount engage... I drove around for 2 hours thinking maybe it was frozen up and just needed to unthaw. it still dont work. so, I tried it in 4-low. 4-low works fine, except it dont turn the front wheels... how do I diagnose this? how does it work? is their 2 engagement points or just one? its automatic lock, no hubs...
 
#3 ·
correct it is the floor shift one. I checked the vacume canniseter/servo thing. it does suck in when I pull the lever. the light on the shift console comes on, saying its locked in. my expirience has been before, that its not always correct.
 
#4 ·
Steve is right, on my 91 the vacuum servo is under the battery tray, I believe this was different in earlier years. There is a mechanical switch on the transfer case with I think 3 vacuum hoses running to it, this is what locks the front up when in 4 wheel drive. I've had that switch go bad twice on me and have since rigged up a manual switch to eliminate it and the long hoses. I would first suspect the switch or the hoses before I would the servo.

Lance
 
#5 ·
jackflash said:
correct it is the floor shift one. I checked the vacume canniseter/servo thing. it does suck in when I pull the lever. the light on the shift console comes on, saying its locked in. my expirience has been before, that its not always correct.
OK, the indicator sensor is on the front diff if I remember right, right where the cable from the servo goes into the diff. Since it is seeing the cable pulled far enough to trip the sensor I would guess the end of the cable has broken off, or has disengaged from in the diff.
 
#7 ·
there is also a spring clip where the cable goes into the front axle. these clips like to break. if it breaks it will not engage. also as the others said, check the vacuum supply and the vacuum actuator. vacuum comes from a vacuum switch mounted on top of the transfer case on some s-10 models. if the switch sticks no vacuum will go the the actuator.
good luck.
 
#8 · (Edited)
ok, heres whatI got. the transfer case IS engaging. the vacume switch IS working. the cable ISNT busted or came off at either end. the servo has plenty of pull, and has extra travel to go if it needs to. right now i got a vise grips holding the cable in the pulled out position. it seems to me that it is pulled out all the way. I took off that plastic housing on the bottom and everything in there seems to be intact. all it is, is a thick steel rod that goes into the diff. I cant see anything else. so, what am i dealing with here? is there a linkage peice in there that can break? whats going on with this dam thing? btw, how far should the cable pull out? it only pulls out so far that I can just see a hex shaped flat spots on the rod, at the servo
 
#9 ·
well, I found a problem with the front diff. the driver side drive flange, has came out. please tell me there is just a nut in there that holds the axle flange on... that i can put back on fron the outside....
 
#11 ·
http://i33.photobucket.com/albums/d86/ugly--ugly/HPIM1706.jpg

the metal plate on the side will come out and i canf fush the clip out and put it back in? that would be awsome, i think. I donno exatcly how this diff setup is but I'd think, that if the clip came out something else must be broke? if you could take a picture of that diagram for me it would help alot, thanks
 
#14 ·
according to that diagram, there isnt a c-clip on the end of the axle. but a retaining ring, and goes with the plate/seal assembly. so, does that mean that that plate holds the axle in? that, could be a really good thing. since Ihavent got a penny in my pocket...
 
#15 ·
Looking at the diagram I believe that the sidecover/axle/bearings are one assembly. I'm just guessing, but it looks like you should be able to pull it all out of the side, replace the ring and put it back together fixed.
 
#16 ·
LanceM said:
Looking at the diagram I believe that the sidecover/axle/bearings are one assembly. I'm just guessing, but it looks like you should be able to pull it all out of the side, replace the ring and put it back together fixed.

I agree,
I have had a few S-10's and this is how they worked.
The full size trucks work the same way.
Jay
 
#18 ·
That is odd,
I had that happen to me once, but it was my first time doing a cv joint many, many moons ago...

I took it apart and didn't pop it in all of the way... Man was I worried that I screwed something up!....I was only 16 or 17...

I figured the only way to make enough room for it to pop out was to unbolt the flange and drop the front axle or knock off the lower ball joint..

Did you go off road at all?...

If it comes out that easy, there must be something else wrong...

I would start by replacing that little ring or C-clip at the end of the spline
 
#19 ·
jackflash said:
fixed it. so why did it come out? is that a sign of wear?

Its a pretty good sign that you should not engage in any further car pushing. That is an ultra light duty drive train and it wasn't engineered for pushing or pulling.

I am glad it didn't cost you anything being christmas and all. I just cringed when you said you had "pushed a car out of the way yesterday" and it dont work today. I figured a spider left or something.