Rear End Oil Leak

Delpel · Post by **Delpel** » Sun Aug 14, 2005 6:19 pm

I've tried trawling the archives for an answer to my question with out much luck.

I have oil leaking out of the large rubber bellows were it connects the swinging arm to the rear wheel drive unit.

The bike is a 2002 Boxer Cup Replica with 9000 miles on the clock. She is now out of warrenty and I can't imagine my local dealer doing a good will repair.

Is this normal for oil to leak out of this joint at this mileage. My other thought was the outside temp is about 32degC over here in Cyprus and I remember reading a post regarding high temps.

I plan on cutting the zip-tie holding the larger diameter end of the bellows and pushing it back and having a peer inside and clean the area up a bit.

What are the thoughts across the board. Sould I be rushing of to the dealer or should I just keep checking the level in the rear drive unit and watch and shoot.

Yogi Bear · Post by **Yogi Bear** » Sun Aug 14, 2005 7:59 pm

Hi Delpel

I have the same problem at the moment on a 2002 'S' with 23500 miles.

I have been checking the levels and they are fine. I have put some silicone sealant along the bottom half of the rubber gaiter which has eliminated any leakage for the short term.

I'll deal with it at the next service which is very soon...

Apparently a small amount of hot oil goes a long way and makes a hell of a mess...

Hope this helps

RiceBurner · Post by **RiceBurner** » Mon Aug 15, 2005 11:06 am

I think everyone's bike has done this at some stage.... mine twice!

it's either the final drive-box seal or the gearbox output drive seal (the drive-shaft tunnel is empty of oil normally).

You can't tell which it is until it's apart and it's a well known problem so the dealer may well do it under warranty - it's certainly worth asking.

Delpel · Post by **Delpel** » Mon Aug 15, 2005 2:31 pm

Peeled the large diameter end of the rubber bellows back and it was empty of oil in there so no major leaks. Poked around with a bit of absorbant paper and there was a smearing of clean oil on the paper. So it looks like something is weeping/seeping.

When I cleaned it all up I noticed there was oil smeared/sprayed on my back wheel which was a bit un-nerving. I checked the final drive box level and all OK. Pulled the breather cap of and pulled the little bit of foam out and that looked OK. Quick question. There is a hole in the breather cap. Does it matter where the hole points. Nothing to do with vacum effect or anything.

I shall monitor the seepage and get my main man to look into it.

Cheers for the advice.

Desmo904 · Post by **Desmo904** » Sun Aug 21, 2005 7:36 pm

Mine's started doing it now!!!
Just clicked over 9000 miles this afternoon (with her indoors on the back), and when I got home there was all this black gunk below the bevel box. Evidence pointing to the bottom of the bellows.
I reckon you guys talked this up between you.

And...don't give me all this BMW build quality crap. This is already more trouble than I had during 4 years of Ducati ownership.

Rant over - I'll just mend it and carry on enjoying my recently acquired "S" :

adamski49 · Post by **adamski49** » Sun Aug 21, 2005 8:02 pm

Desmo904 wrote:...BMW build quality crap...

FYI you got the word 'crap' in the wrong place.

HTH

Adam

winger · Post by **winger** » Sun Aug 21, 2005 8:14 pm

Remind me of when i shelled out 1300 quid for my Dymag wheels three years ago and found red gunk all over the back'un to find it was comeing out of the wheel!!! but really is another story.

Although Beemers are notorious for spewing out of the back end cleaned my wheels this morning just as bad after a thrash to Silverstone,like an dirty oily mist!!!!