I've got a '96 2WD 5.9l with 46RE with new ball joints, wheel bearings and shocks (in the last 12 months) and it will make a "clunk" whenever I let off the accelerator.

It will not make the "clunk" going over bumps or turning, ONLY when I let off the gas. The "clunk" is coming from the driver side floorboard.

Any ideas?

 

Sounds like your driveshaft you joint is going out. Crawl under your truck(make sure its safe of course). Then grab the front of the shaft at the tranny and see if it moves up and down or side to side. then do the same at the rear diff.

Josh

 

It might also be the motor mount. I have been having this issue on my truck only on the passenger side and I am convinced that it is the motor mount. I just haven't had a warm enough day and the money to replace it.

 

Motor mount sounds logical, given the deceleration issue. I'n not sure how to check a motor mount, but I'll look into it

 

if the lower shock bolts are not torqued at 100 lbs they'll knock.
a wallered out bolt or bushing can knock also.

 

my tranny mount was shot, and mine jumped on acceleration, and sometimes on deaccel.......My mount actually came out in two pieces lol. the whole mount was separating when i took off...and the mount only cost me 20 bucks