maybe slop in the slipyoke. grease the slip yoke.

 

sounds like it's coming from the front, and no noise in 2wd

 

that's a possibility . I would rule out where the sound is coming from 1st. When my dads truck had clunk problems with the tcase. We jacked up all 4 tires and drove the truck in 4wd while I sat next to it looking under to see where the clunk was coming from. Its really a 2 man job. But it turned out being the transfer case chain was slipping on us.

 

have an '04 Jimmy 2dr with manual tranny
on acceleration in 4hi the front axles start to clunk but disapears when cruising
there was a post regarding a TSB in 2003 regarding this problem that started to discuss this issue but left off before any advice making one have to subscribe at a price to get the rest of the TSB. Can anyone help with this poblem?