DCWinterXJ

Man my XJ makes tons of noises I can't identify....but runs great, full of fluids, and none of them are rod knock. So I can deal. What cruiser54 posted did indeed happen to me. The hanger rusted where it was connected to the exhaust pipe and broke off...essentially freeing the pipe to whale on the cross member. That is a perfect picture Cruiser! He has helped me many times. Anyway we wire brushed off the rust and spot welded the hangar back on and woohoo no more uncontrollable banging. From the OP's video I can't really hear the banging scenario. If I used headphones or plugged into my home theater maybe...phones try too hard to eliminate ambient noise. Not sure I am very helpful. Some guys have said if you replaced the camshaft position sensor it can sometimes hit the flywheel. And of course always check the flywheel/aka flexplate bolts. If they come loose they will bang crazy. Good luck...keep searching!

remdev

My issue turned out to be the front differential. I have not torn it down yet so not sure whats going on with it; but at 243k I'll just rebuild it.

DCWinterXJ

Wow! Was it making noise while disengaged? That is pretty crazy. How did you find out?

remdev

I took it to a muffler shop and they pinpointed the noise. Muffler shop? I know. I know, but they were the only ones willing to to be paid just to diagnose the sound and not repair. They put it on a lift with a body in the drivers seat. No noise in drive (no front wheel spin so no axle or differential rotations).

The it was put in 4WD High and the noise was heard so they walked around with a stethoscope and checked the engine bottom end, transmission, TC, and differentials. The front differential was the source of the noise.

The XJ is an EDD for me so I don't have the time to work with it. Plus, after watching a few videos on the work I don't have the spreader tool and the pre-load can be a little touchy. If it were a project car I might think about it after making a spreader. Calling a couple of transmission shops today. Depending on the pricing I may end up doing the work anyway.

cruiser54

why not grab a junkyard rear axle assembly?

remdev

Transmission shop is going to take a look for $138. Depending on what they find and a cost to fix, a junk yard assembly may be the best option.
More to come
BTW, nice site cruiser54