MrE36

BMW E36 · Engines

Main Seals

MrE36 house reference

An oil leak at the very back of the engine, dripping from the bellhousing area, is usually the rear main seal — the crankshaft seal where it exits into the gearbox.

The catch is access: it sits behind the flywheel, so reaching it means separating the gearbox and removing the flywheel — which is why owners almost always do the rear main seal as part of a clutch job rather than standalone Clutch Replacement.

The front main seal (c