1988 GMC 4X4 major problems!!

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token2004

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Okay, so the truck is a 88' with the 241 transfer case I think. 4X4 worked PERFECT prior to me pulling the t-case and changing both the front output and rear output bearings. I had the case completely apart and didn't notice anything wrong, re assembled it and had no misses left on the bench when I was done. The same day I put it back in the truck I also added a 3 inch body lift and didn't hook the linkage back up until I was done this. As it sits right now when in 4lo the lever sits pretty well right at N and when I try and go into 4HI it hits the end of the console. It engages 4LO with no problems but after driving for a few seconds it randomly pops out into neutral. When I try and put it in 4hi the light wont come on but the front yoke on the t-case spins with the back. (no front shaft and rear wheels off the ground) but the front diff doesn't engage. The actuator is working obviously because 4lo will engage.
Today I went under the truck and disconnected the linkage completely.. I shifted the t-case into 4hi with a wrench and you can feel it go in and the front yoke engages for sure but still the front diff wont engage. A friend of mine says its linkage but I dont think thats possible at this point because the lever doesn't actually lock it anywhere.
I wanna go wheeling on Sunday but if I cant get this fixed I guess im out!!
 

dave_erald

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Check your body lift kit again and search online. Those kits (the good ones) come with extensions for just about everything from radiator fan shroud drops or instructions to cut as well as extensions for steering shaft and shifters if needed. It sounds like what you need is to lengthen the linkage to the t-case. Most likely the inside of the case is perfectly fine. As for the popping in neutral the lever may not be pushed far enough to catch the detent in the case. And the front axle not engaging, check your switch on the top of the case and you could still have the old style slow actuator on the front axle. Old ones were yellow and terribly slow at engaging, sometimes not at all. New ones are black and come with upgraded harness. Good luck.
 

badazzbulldog

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its the linkage you have to adjust the rod at the shifter end it should be threaded,undo it put shift in 4hi position and spin the piece that attaches to shifter down the rod till it lines up
 

token2004

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its the linkage you have to adjust the rod at the shifter end it should be threaded,undo it put shift in 4hi position and spin the piece that attaches to shifter down the rod till it lines up

with the transfer case completely disconnected from the linkage the linkage moves freely back and forth.. there is nothing that locks the lever in hi or lo so why would it pop out? Even if I go under the truck and switch the t-case with a wrench you can 'feel it' engage 4hi but still nothing.
Last night i tried putting it in 4hi while going about 20km/h and I heard a grinding sound that was so bad im surprised i have a t-case left.
And the P.A. body lift instructions say there should be no adjustment needed.
I think im just going to park this thing for awhile... its a mud truck that hasn't seen mud in months because every time I fix anything something more major breaks.
 

great white

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Front axle switch for the TLA or the TLA itself is crapped out.

Does the truck move at all when you manually pop it in to 4hi?

Ie: is it rwd only?
 

token2004

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Front axle switch for the TLA or the TLA itself is crapped out.

Does the truck move at all when you manually pop it in to 4hi?

Ie: is it rwd only?

TLA? what is that? If you mean the actuator I tried 2 different ones both of which I know work. Yes if I put the t-case to 4hi I still have rear wheel drive.
I dont have a front driveshaft on right now and in a gravel parking lot I just put it in 4lo and held my right foot on the lever to hold it in placer so it wouldn't kick out. Whern I did that it stayed in LO but every time I gave it a shot of gas the switch lever kicks back very aggressively. Now after I did that the indicator light wont come on at all but I do have the older actuator in there so I can easily just swap that again.
 

token2004

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Basically for my wheeling trip tomorrow Im going to cut a peice of wood to jam into my shifter to hold it in 4LO, if it blows up who cares.. not this guy!
 

token2004

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Basically for my wheeling trip tomorrow Im going to cut a peice of wood to jam into my shifter to hold it in 4LO, if it blows up who cares.. not this guy!

So I guess it really must just be the linkage... took the t-case back off because of a leaking seal and it switches into all gears with no problems on the bench..
 
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