BMW E90 Rear Differential Axle Nut and Seal Tool Kit

This is the ten-piece kit for pulling the rear final drive apart on a BMW without rounding off a flange nut or chewing up the input shaft seal. It covers the collar nut between the rear drive shaft and the differential, the differential flange nut, and the output flange itself, and it replaces the factory specials 335040, 335050, 335060, 335080 and 230020.

Three input shaft seal sleeves are included so one kit spans most of the range. The 34-tooth socket is the common one and fits E70, E71, E72, E82, E84, E90, E91, E92, E93, F12, F13, F20 and F25 finals. The 27-tooth socket covers M2, M3, M4 and M5 differentials. The 37-tooth socket is for the later 7 Series. Count the teeth on your flange before you start — the socket has to seat fully or you will deform the nut.

The job it solves is the leaking pinion seal at the front of the differential. The nut on that shaft is torqued hard and staked, and the flange spins the moment you put a wrench on it. The output flange support wrench locks the flange while the inner nut wrench breaks the collar loose, so you are not jamming a pry bar into the ring gear. The seal sleeves then let you slide the new seal over the shaft splines without cutting the lip — that cut lip is why a lot of reseals come back weeping a week later.

Everything is hardened steel and comes in a blow-molded carrying case with a pair of gloves. It is a reusable bench tool, not a one-job consumable.