Originally Posted by Z K
Yeah, BMW also has a non-FM boosted LSD diff fluid. Much cheaper than the FM booster version. Dunno the part # off the top of my head.
The FM-boosted version has more FM in it for people who complain about diff noises. Most of the time the noise is because people drive the cars too conservatively and don't break in the differential.
Merc still sells it a lot cheaper... its about 10 bucks cheaper..