Horrible Vibration (Pounding) in Rear End, 1991 F-liner FLD-120

bent rim maybe??

 

Get on a cell phone and a buddy riding next to you on the right then the left and try to determine where it's coming from. Might be able to narrow down your search. This is a real tough problem to find!!! I know!

Ride height
Bad wheel bearing
Bad universal joint. If you recently had your rear end hopping up and down trying to get out of sand it can damage them real quick
Drive shaft out of balance. Some have weights welded to them and they can come off

 

Had the same truck same problem,vibrate at only certain speed only when empty,after taking it to three shops and dropping the drive shaft twice took it to a drive shaft shop,drive shaft wasnt balanced one yolk was missing the lip that keeps the u joint in place.problem solved.i advise you to fix it asap cause the vibration will brake the driveshaft carrier.hope this helps

 

You can adjust the ride height like 1/2" and take it for a ride then try the other direction.

 

I meant a 1/2" on the level rod not the truck height.

 

The title opens too many doors for jokes. I know this doesn't help, but...

 

LMAO...Ya know. I was going to say something but I decided not to. Something about prison trucking or like that

 

Went to dealer once and said my rear end was leaking. Everyone lost it