So my '99 F350 4x4 is making a clunking sound and there is a distinct jolt in the truck while this is occurring.
From a stop while accelerating, there is a distinct jolt and clunk. The best way I can describe the feeling is like something isn't tightened down all the way so there is a split second while inertia is generated and the "looseness" catches up to the acceleration.
When stopping, the clunk and jolt is generated when the truck comes to a complete stop. When the truck rebounds backwards a bit because of the suspension pulls it backwards after stopping, you will hear the clunk again.
I replaced the ball joints a week ago an a wheel hub bearing on the right side. I don't recall this before these repairs, but it may have been making this noise. I was more focused on the grinding from the wheel bearing so I may not have noticed the clunk and jolt then.
Any thoughts on where I should start looking for the problem?
I have had bad U-Joints behave that way too. Once I had a U-Joint that only had one of the four bearings go out so you couldn't feel it by hand but the truck's torque caused it to move enough to make it clunk on acceleration and deceleration.
I had an issue almost like this.. when stopping hard and keeping the brakes held, once I let off the diff would unbind and you could hear and feel a clang..greasing the splines on the drive shaft going into the transmission was the fix..
try this link or do a search under my name or "mysterious-thump....Some other bits of useful info here too. Scroll down to the bottom of page 1. Then the grease PN is on page 2. Yes only use the FOMOCO grease! I learned this the hard way.