I've had my truck (1999 F150 Reg Cab 4.6l 4X4 Auto with 44k miles) for about a month now and a couple days ago it started making a "clunk" sound when going over bumps. It doesn't really seem to be bother when turning unless it's an uneven grade turning in. I've tried compressing the suspension (jumping on the bumper) while parked and no noise. The suspension components look fine so I'm leaning towards maybe a tranny mount. It does seem to sound like it's coming from the center or rear of the truck while inside the truck. I do know enough about autos so if you do have any ideas I will know what your talking about. I'm waiting for the wonderful weather to leave New England before climbing under and taking a really good look at things. So if you have any known issues with these trucks let me know what you think...Thanks

 

I'd check the ball joints and shocks first.

 

I have read about some of the front end parts being high wear items but with 44k on the truck and the sound appears to be from the rear I figured it would rule ball joints out. I did give the shocks a look over all around and they look fine. I would think that if it was shocks I could reproduce the sound by jumping on the bumper like I was (front and rear) as well. I guess I will just have to get under it and really see what's going on but I will check out the ball joints. Thanks for the ideas....JJ

 

this may sound stupid but check the spare wheel they can come loose and they will make a similar noise other wise just start at the front and work your way back

 

Checked that as well. Turns out that it was a broken end link on the sway bar. So on Saturday...new links and a Lightning style exhaust from Ford Racing will be installed.

http://s58.photobucket.com/albums/g2...nt=exhaust.jpg


Thanks for the ideas guys.......