Deep thud when wheeling/hitting bumps

[cp2295]

Hey everyone, my jeep has been making this awful deep thud when I'm wheeling especially going over lumps/rocks on trails (if I'm crawling it usually won't do it). Also if I punch it from a stop it'll repeatedly thud.. Only happens if I hit the throttle hard. Minor bumps in the road don't make it happen, I have checked everything on the front end. All my steering, control arms, trac bar everything is new and I have retorqued it all just to be sure. Cannot find a single loose part. I can feel it in my feet, right below them, had a buddy wheeling with me and he says it feels like it's on the drivers side too (he was sitting on the passengers side when he said that..) I've even checked the trac bar bracket mount. Drive lines are nice and tight, tranny mount is good, haven't checked the engine mounts yet. It's a very concerning thud, not a minor shock clunk or anything.. It's a deep thud! Thanks for the replies let me know if I need to be more specific!

 

[cnugent]

Yeah, I'd check motor mounts. Have someone hold the brake and shift back and forth from D to R while you are watching the mounts. See what happens.

 

[tonytech]

Have you also checked the torsion bars?

 

[trippled]

Have you also checked the torsion bars?

Uh what? No torsion bars on xjs. Check control arms too. When my re arms wore out they thumped like crazy

 

[old_man]

Shock bushings?

 

[ehall]

The trans mount is designed to yield a huge amount of movement. On my jeep the transfer case was banging into the skid. It might also be letting the exhaust bang into the floorboard or something. Look for areas with tight gaps, and check for contact wear spots

 

[nectarXJ]

Check control arms too. When my re arms wore out they thumped like crazy

x2.

 

[cp2295]

Can't be control arms they're new and I've checked the bushings for play with a pry bar but I've never thought of the exhaust banging against the body.. That's right exactly where i feel it, I'll have to check the mounts and make sure the exhaust hasn't been banging against the body.

 

[Brenden80011]

It's most likely your exhaust somewhere after your tranny. Mine does it now but that's because I don't have the bracket in the rear due to my bumper brackets.

 

[cp2295]

Figured out the issue.. I basically have no motor mount on the drivers side