Hi guys, I'm new to this forum and have been looking around but nobody has seemed to have the same problem as I am having right now. Ok, so here's the low down, I have a 96 k1500 silverado 4x4 with a 4l60e transmission. I had recently been having trouble with the tranny acting like it was in neutral in 3rd and OD. I brought it to a shop, they supposedly looked it over and told me my cluches were bad. so not wanting to dish out 2k on a rebuild i decided to swap out a tranny from a 94 k1500 gmc. I switched the gearshift spline and all that jazz to make it fit in my truck, so no problems there it bolts right on and the transfer case bolts on and all is right with the world, but now i thnk my transfer case is junk. I adjusted the 4x4 shift cable, but the tc keeps jumping in and out of gear (2h-N) Now it wont even shift into any gear but occasionally decides to engage in 4L. Th tc is also making a nast rattling sound which leads me to think maybe something snapped inside? I dunno but I'm running out of patience for this truck!

 

sounds like your transfer case is junk

 

Ok now this is weird, I haven't had time to mess with the truck lately, I was also debating getting another transfer case. So one day I started the truck up just to keep the battery from dying and I got curious. I decided to see if the truck would move under its own power, to my surprise it did! For about 5 min haha! The transfer case engaged in 4l, 4h and 2h for about 5 min then all of a sudden the truck just lost all drive again and now won't move. So i dont think the transfer case is to blame, Im thinking that possibbly the tranny cooler lines might be clogged? what would happen if this was the case? would the tranny being to hot make it jump into a limp home mode or just drop the truck into neutral? is there any electronic issue i should look at before even doing that? Any help would be appreciated!

 

Was the trans from the 94 a 4l60e? If it was not electronic you would need to install the kick down linkage.

 

The tranny was from a 94 and it was an electronic 4l60e not a 4l60. The only differences between the 94 and 96 4l60e's were the neutral position sensors and the shift lever spline that was longer to clear the neutral position sensor. I replaced the neutral position sensor, and swapped out the splines and all the other electronics were in good shape and plugged right in. The 4l60e was used on all models after 1992 I believe. But i checked the numbers just toe be sure and I was told that other than those two things the tranny should be a direct bolt in.

 

Ok so I did a little experiment just to see what exactly might be causing this problem. I drove the truck today until it got to the point after about 5 min where it just wouldn't engage in gear anymore. I turned the truck off an tried again to the same problem, the truck just wouldn't engage any gear. So I sjut it off and left it sitting in my parking lot, and waited several hours for it to completely cool off. When the truck was completely cooled and so was the tranny and transfer case I started it up again, shifted into drive, and the truck took off without hesitation. It worked in 4h 4l and 2h like normal again, I didnt wait till it stopped working this time thought because I needed to park it in its spot. But something tells me it is a heat related problem, because every time the truck gets up to about half operating temp it disengages all gears and goes nowhere, but when it cools back off it works fine.