[1988 jeep yj]

I did away with the stock trany mounts and installed chevy 1/2 ton mounts. of course this does take a few modifications to make fit. That fixed the problem for me. I also had a problem with my mounts braking.
I think the bolts are 10mm and about 2 1/2 in. long. Have you tried something as simple as a lock washer? Might work.