OK, I have a 2001 5.9 4x4 quad cab. it has recently started with a very annoying squeak while in gear. i say while in gear because if you pop it into neutral it stops, drop it in gear and comes right back. ( it is an automatic) i did a bunch of searching and reading before asking, and the general thoughts on here and other info sites lead me to the u-joints. changed the rear drive shaft joints out today ( i did the rear cuz it was doing it in 2 WD.) and the squeak is still there. i have spray lubed all the body mounts,trans mounts,front u joints,replaced the belt, sprayed the exhaust mounts as well. my son suggested it might be the rear end. i am really at a loss here. any other ideas,or suggestions?

 

these trucks have weak transmissions, it may be time for a rebuild especially if you've towed. how many miles?

150K out of a stock tranny is good. ive seen many go before 110K

 

put the rear end up on jack stands and run it to see if you can reproduce the sound in the drive train.

also, there's a pair of nylon bushings on the auto trans linkage under the drivers feet that tend to squeak.

 

i've only owned it a few weeks,so i'm not sure how much if any towing has been done. it has 142000 on it, however the tranny was replaced under extended warranty at 82000 by the previous owner. i have spray lubed all the movable parts of the shift linkage already. i'll double check to insure i got the nylon bushings you spoke of. (i assume they are part of the shift linkage?) i have not set it on jack stands to see if it can be duplicated. that will be next unless someone comes up with a better plan before i get a chance to borrow the heated shop again. THANKS!!