In Reply to: How easy to change tranny and differential fluids posted by Nikolay on January 26, 2000 at 16:40:59:
I have a1994 530ia and changed the differential fluid myself - refilled with Mobil 1 synthetic gear oil. You need a 14 mm allen wrench (available from Imparts for about $14). However, the transmission has no dipstick and must be filled from beneath the car at the correct temperature - it is a job best left to an experienced BMW mechanic. I had mine done at the dealer but I provided the fluid (Mobil 1 synthetic ATF). This is an excellent replacement fluid for the DEXRON II used in your transmission (ZF 5HP18-EH). I think I was charged about 2 hours labor for it. A word of warning - you must be meticulously clean when changing the transmission fluid. Any lint or dirt that gets in the transmission can ruin it.