Rear Main Seal

**simmo** · #1 26 Jul 2004

Hello wise ones of things BM

Pulled apart the G/S to freshen it up and resolve the ongoing gearbox problems. The Clymer says you can prise out the rear main seal. i have managed to mangle it but not remove it. I noticed in another manual that a...BMW special tool! is required to place the new one in. Is it true! Is there a trick to this.

cheers

alec

**Fritz** · #2 26 Jul 2004

Not sure if you're talking bearing or oil seal Simmo, but this is about replacing the seal and keeping it oil tight http://www.ukgser.com/forums/showthr...ht=output+seal
Be useful anyway. Search the GS site and you might find what you're after, or post a query. Cheers, Fritz

**Timo** · #3 26 Jul 2004

I had to do this job twice when I was 'freshening up' the bike - very frusterating to get it all back together, push the starter, and watch oil stream out from under the trany! I mistakenly tried to push the rear seal over what I (and the BMW mechanic that was helping me) thought was the crank shaft, but what turned out to be a removable collar.

Check that everything has been removed - my Haynes manual was not to specific about this, which partly lead to the above mistake. Make sure you measure the installed height of the existing seal before removal (how deep it sits in it's seat). I used a section of pipe to drive the oil seal in to position. You need to find the right diameter that will press on the hard outer shell of the seal. I can't remember the size I used, but it was fairly common - 3 inch I think. The newer type seals should be soaked in oil for 3 hours before installing. Good luck!

**foz** · #4 30 Aug 2004

Simmo,
make sure you replace the o ring on the crankshaft boss,else the oil leaks behind the flywheel adaptor and you end up stipping the thing down to replace the seal a second time...like I did ..not knowing about the o ring,also changed the oil pump back plate and seal to be sure,now cruise at 100 mph and it's dry as bone.Voila!!