I have searched, and been under my car for 2 days, looking, removing, replacing, checking, and still have this "thump"
It seems to be most noticable on the right side, when going over rough roads (ie, RR tracks, washboards, pot holes).

You can see in my sig. what I have done to the car, and those are the areas that I have looked into.

I removed a rear shock, and drove it, thinking if it was bad, and not there, the noise would be gone, not true.
Same with the right side sub frame conn. (mine are bolted on for now).

Removed the rear sway bar, and checked all its mounting point.
End-links (front and rear) are new, tight, and in-place.

The track bar, torque arm, brake calipers and front struts (and upper bearing plate) are tight and in-place.

I don't know if anyone will have anything to help, but thought I'd ask, because I have just about ran out of areas to look for this thumping, and have not found it yet.

Trust me, I know things like this are not the easiest to figure out, just looking for your thoughts.

Oh, and I do NOT have any issues with the exhaust and the sub frame connector, (no cat).

Thanks,
Leon.

 

Does it seem to come more from the rear, as everything you have said you've checked comes from the rear.

Does it appear your bottoming out on the bumpstops?
Rear hatch rattling?
What about front suspension? Strut mounts?

 

Thanks Dale,

It seems to come more from the rear.

It's not the hatch, as it sounds like it's coming from somewhere lower.

I have new upper strut mounts on the front, along with new struts, and everything up-front is tight.

When I do hit a spot on the road with the right side of the car that will make the noise, I don't hear the thump until the right rear goes over that part of the road, so I don't think it's coming from the front.

I still have the stock LCAs and PHB. I'm thinking maybe the bushings are shot in one, or all of those parts! More so the LCAs maybe?

I don't think the car is bottoming on the bump stops, 'cause sometimes it will thump without alot of suspention travel.

I also have a new trans- mount, and the cross member bolts are tight.

This sucks!

Good ideas, though! Thanks for the input!!

Leon.

 

Sounds like your ball joints. Try lubing them and see if the noise stops or gets quieter.

 

Ahh, forgot about panhard.

Yes, mine did that . Top right side. Center bushing got wollowed out.

Crawl under car, and have someone else shake it from side to side. Watch that joint.

 

Spare tire/jack/bracket lose?

How about a worn out axle bearing?

Loose caliper bracket, caliper bolts, broken drum brake spring, PB cable slapping against the housing?

LCA bolts not tight enough (I found that when I installed some spohn LCA relo brackets I had to hit the through bolts with an impact gun before things got tight enough that I wasn’t getting a thunking)?

How about a rusted pivot bolt or bushing sleeve allowing them to slap around? Or a disintegrated bushing?

 

I chased a right rear thump for a while.....ended up being a worn LCA bushing. Try to move the LCA laterally.....if any lateral play, then it needs replacing. My LCA at the axle was slapping back and forth.

Also....I torque arm bushing can sound like a big knock during gear change during acceleration. It'll sound likes its coming from the right also