differential clutch pack retaining ring bolts loosen?

I have read from a few e36 FAQ's that the final drive clutch pack retaining ring bolts may back out and cause a ticking sound and eventually failure. Is this issue only on limited slip differentials or can this happen to non-LSD cars?

I have a 95 325iA that has an odd "popcorn" sounding rattle noise coming from the rear wheel area. It's sort of intermittent noise that seems to happen on perfectly smooth roads

Your "ring bolts" would have come undone long before now, suggest you have a driveshaft joint on the way out, or prop shaft joint,clutch pack bolts coming undone cause all sorts of trouble quickly, a matter of ten miles or so.