1990 F150 drivetrain help

[buttersgt350]

Im pretty sure it needs u-joints but maybe more. It clunks when i shift between park, drive and reverse. Also when cruising down the road if i let off the gas and get back on it there is a pop sound coming from the rear. I can only hear it if i have the slider window open. Im sure there is someone on here that is good with rear ends and might be able to diagnose/fix. Thanks!

[Prince Valiant]

keep the slider window closed. Problem solved :goof

[The Shaolin]

There is always some slop in the joints, sounds normal, somewhat.

Jack one rear wheel in the air, wiggle it back and forth and see what's moving. I traced mine back to the transfer case, prolly pretty normal.