I Have A Clunking

ok so i'm new to the forum....very happy to find that one existed...anyway was wondering if anyone could help me out.. i have a 90 xj that about 5 months ago i replaced the front and rear differentials bc i blew them at the same time crazy story...but at the same time i took the transfer case out and replaced the chain and put all new bearings and seals all wearing was normal nothing damaged but the chain was strected out pretty bad. so the question is when i am at a stand still and i go to step on the gas at the this low speed or stop there is a clunking that increases with the rpm untill the jeep is rolling nice...now i looked at the undercarriage and nothing is hitting the motor trans or transfer case and to further the investagation about 1.5 years ago i put new motor in and motor mounts. and i also put i new transfercase mount in when i put the case back in someone anyone please help.........

Double check the point where the exhaust passes over the crossmember. Although usually a new transmission mount will keep it up, the clearance is very small, and if the mount or the rubber hanger is worn it can clunk at low speeds, especially when you're accelerating.

If yours is an automatic you might also want to check for loose torque converter-driveplate bolts.

Finally, don't overlook the driveshaft. A dry u-joint can make some nasty noises, even though it won't always show any play when you shake it. You probably checked/rebuilt all that when you replaced the diffs, but if the joints are old and you're at a dead end, you might try disconnecting the shaft at the differential and testing the joints for binding.

yea i checked everything and i still have nothing, but the sound, sounds like that it is coming from under the shifter you have anything with that????