clunk/vibration sound

I have a sound coming from seat area up. I don't even know what to search to get a clue, but to my best description it makes me think of a coil spring bouncing between its perch, but its not brash metal sounding. A rapid thud of something reverberating noise. It happens over bumps like something is batting up/down.

.Trans mount is solid
.control arms feel solid, no play
. engine mounts look fine (brown dog)
. all shocks fastened securely
. trac bar tight
. exhaust tight

I have some in/out play on the TC front output yoke, no up down, nor pinion or driveshaft play.


I wouldnt even write this but its the weirdest sound to think about where its sourced from, Im not sure I can get audio of it, Ive been prying on everything under the jeep to get hopefully find this.

Anything this makes you think of Ill gladly check!

oh and this has been with the sway bar connected and disconnected.

Gear box spacer cracked? Check the frame for a crack by the gear box. Then again, if this was so, I'd think you'd have DW.

steering box brace is still in one piece.

Could be your rear driveshaft slip yoke joint making the noise.

Another thing to check is your transfer case shifter linkage the bushing go bad and can cause a vibration apply slight pressure to lever while moving see if the noise goes aeay.