Rear end thumping

[Davids91]

2001 Ford Exp.Sport. Just bought this spotless wonder. White and perfect..ALMOST...a loud read thumping from the rear under acceleration. Sounded like an exhaust pipe or loose muffler, broken sway bar bushings or a broken shock. NOPE...then I thought it was the wiper motor fell in the rear hatch door. NOPE. My mechanic thinks its body bushings? PLEASE....never saw them go bad. I have read that simple U Joints can cause this? Had them checked and they are OK. The thump is LOUD.... HELP!

 

[shaggymane]

91 Ford Exp.Sport. Just bought this spotless wonder. White and perfect..ALMOST...a loud read thumping from the rear under acceleration. Sounded like an exhaust pipe or loose muffler, broken sway bar bushings or a broken shock. NOPE...then I thought it was the wiper motor fell in the rear hatch door. NOPE. My mechanic thinks its body bushings? PLEASE....never saw them go bad. I have read that simple U Joints can cause this? He never checked them though. HELP!

Yes, a bad u-joint can make a noise like that and it's so easy to get under there and check. A bad U-joint can also make a noise like a pebble in a hub cap.
Personally I think a car can make every known sound in the universe. It's just figuring out yours.

 

[Davids91]

Rear end noise.....further investigation.

I hope to get it on the rack today and spin the rear end in hopes that it makes the same noise while not moving. I will keep the board posted. fingers crossed.

 

[Davids91]

Not the rear end or U Joints...Any thoughts? They keep telling me body bushings?

 

[little x]

Have you looked at the body bushings? If they are mauled it could be the culprit.

 

[Tony H]

Bad rubber grommets on your shocks?

 

[little x]

No one put zipties around your drive shaft did they? Old prank, causes a ton of racket.

 

[Davids91]

Yoy got it

Have you looked at the body bushings? If they are mauled it could be the culprit.

Its the right rear body bushing. I can bar up the body off the frame about a quarter inch. Slipped a piece of rubber in between and the noise stopped. Any Idea how much work or cost to change them both?

 

[little x]

^^ haha, couldn't trust the mechanic, could you!

They don't cost much, but they are sort of a pain to deal with. Read the how to threads on body lifts. What you need to do it undo the rear 2 bolts, slide out the old mounts and push in some new ones. But, you may need to loosen other body bolts near the back to give yourself enough play to get the new ones in there. You might just want to get a whole new set and replace all 10 of them while your doing it. It will give your truck a slightly better ride, just a little more lift (they tend to sag and compress with age), and keep you from doing the same thing to a different corner in the next year.