BMW Type 210 Rear Differential Bearing and Seal Kit

This is a bearing and seal overhaul kit for the BMW Type 210 medium-case rear differential. The 210 case was used under the E23, E24, E28, E31, E32, E34, E36, E39 and E46 chassis, including M3 and M5 applications, and the kit works with both open and limited-slip carriers.

Inside are four tapered roller bearings with cups (the two pinion bearings and both carrier bearings), two carrier side oil seals with their lock rings, two O-rings, a pinion oil seal, the pinion nut securing plate and a new crush sleeve. It cross-references BMW 33121205138, 33121204657, 33107510289, 33121213949 and 33121206294, plus Timken-pattern numbers JLM104948, JLM104910, HM803149, HM803110, HM89410 and HM89448.

The typical reason to open a 210 is a howl on the overrun or a growl that changes with load, which points to worn pinion bearings, or a weeping pinion or output flange seal. Mark the carrier side covers before pulling them, since they set carrier bearing preload and backlash. Keep the original pinion depth shim, press the new bearings and races in, and tighten the pinion nut against the new crush sleeve until you reach rotating preload without backing it off. Reset backlash, check the tooth pattern with marking compound, then fit the new side seals and fill with the correct gear oil for an open or LSD unit.