[jackflash]

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...

[1931 steve]

This has the shift lever on the floor correct? All you did is engage the transfer case but not the front axle, there is a servo under the battery, that normally fails, you may want to check this out.

Steve

[jackflash]

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.

[LanceM]

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

[LanceM]

Originally Posted by jackflash

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.

[poncho62]

Chances are, the cable is just not pulling far enough to engage the gear in the front diff....check for vacuum leaks, lubricate the cable etc.

[craigaliddle]

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.

[jackflash]

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

[jackflash]

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....

[LanceM]

Sorry, from the exploded diagram it looks like a C clip, they call it a retaining ring. From the picture it looks like the whole assembly will come off the side of the diffy with the cover plate on that side.

[jackflash]

http://i33.photobucket.com/albums/d8...y/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

[poncho62]

You will have to take the cover off, chances are, the end of the shaft has broken off, where the groove is that the "C" clip fits into.

[LanceM]

Wish I had a scanner for stuff like this. Heres a pic of the diagram, hope it helps.

[jackflash]

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...

[LanceM]

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.