My "new" 1995 525i has 98k miles and unsure when/if the PO last changed the auto tranny fluid. No problems with performance ( GM A4S 310R ) - just bothers me not knowing. Here is my "cautious" ( anal ) approach in case the fluid has never been changed:

1) Drain pan only and refill with Mobil 1 Synthetic
2) Drive approx 500 miles
3) Drop pan & sump, replace fluid, new filter, gaskets and Mobil 1

The thinking is the first change should allow the Mobil 1 to clean out/loosen crud, the second get it out of the transmission. This seems to be the common theme in previous posts. Any other thoughts?

Also -is there a crush ring on the drain bolt? Can't find any listed on parts websites and my filter service kit doesn't have one.