This just started to happen recently.. Whenever I hit bumps (not small bumps, but when there is a decent sized dip in a trail, i'll hear it) I hear a thudding noise like something hitting the bottom of my jeep. It's not a stick or anything, because it happens on all bumps.. I also looked under my jeep and I can't find anything loose.

Any idea what this might be, of if it's something I should worry about?

NOTE: It also did it when I turned off/started my jeep maybe 2-3 times, but it stopped doing that..

Thanks

 

Check all of your bushings, motor mounts, and tranny mount.

 

I think that's what happens when the bushings on the upper shock mounts wear out.

 

mine does the samething and it is the trany mount,my exhaust thumps around to making the same sound.

 

My 91 made a very similar thumping sound (I equated it to the sound of someone hitting my floorboard with a rubber hammer). It started right after I got off a trail and was on the hour long drive home. It ended up being mud and rocks that had accumulated on top of the cross brace below the tranny, just enough so any motor twist or decent bump would thump loudly. Just scraped everything out with a long screwdriver and haven't heard it since. Hopefully your thumping is as easy to remedy. Good luck!

 

Thanks for all the advice. It actually ended up being my muffler; the bracket holding it up was broken. I'm surprised I didn't catch this the first time I checked.

Thanks to everyone who supplied some possible remedies!