Oil leak, final drive, not seal / bearing

[mylovelyhorse]

That troublesome bearing and seal on the final drive that I've had such fun replacing & recitfying on my 1999 R1150GS appeared to have leaked again. So this time I took the bike to a BMW chap (ex-Bahnstormers) for a more expert diagnosis.

The seal is fine but oil is leaking from where the wheel nuts bolt into the crown wheel. He says that he's heard of this before, although it is very rare, and that the only solution is to replace the diff.

Before I lay the bike up for a few months until I can afford to replace the diff, has anyone heard of this and do they know of a way of repairing it?

 

[bumpmuncher]

That troublesome bearing and seal on the final drive that I've had such fun replacing & recitfying on my 1999 R1150GS appeared to have leaked again. So this time I took the bike to a BMW chap (ex-Bahnstormers) for a more expert diagnosis.

The seal is fine but oil is leaking from where the wheel nuts bolt into the crown wheel. He says that he's heard of this before, although it is very rare, and that the only solution is to replace the diff.

Before I lay the bike up for a few months until I can afford to replace the diff, has anyone heard of this and do they know of a way of repairing it?

oh dear had that problem with my fd on my airhead
http://www.ukgser.com/forums/showthread.php?t=108806
cray motorsport faversham kent may be able to help other than that the lower cost option is to find a reasonable price used one. there was one in fs&w the other day

 

[ianboydsnr]

That troublesome bearing and seal on the final drive that I've had such fun replacing & recitfying on my 1999 R1150GS appeared to have leaked again. So this time I took the bike to a BMW chap (ex-Bahnstormers) for a more expert diagnosis.

The seal is fine but oil is leaking from where the wheel nuts bolt into the crown wheel. He says that he's heard of this before, although it is very rare, and that the only solution is to replace the diff.

Before I lay the bike up for a few months until I can afford to replace the diff, has anyone heard of this and do they know of a way of repairing it?

is it abs or non abs?

I have a spare non abs r1150r diff, that I could probably loan for a few months

 

[davegs]

Leaks

What about jointing compound around the bolt threads, it is not pressurised
so have a go. And a belvel box is NOT a diff.
dave GS.

 

[bumpmuncher]

What about jointing compound around the bolt threads

thats fine if you just want to mask the issue. Ask proff about his 100mph getoff due to a locked up bevel drive

 

[davegs]

Bevel box

If your loosing that much oil there's something very wrong and why are you using it? a slight weep won't make it seize up and belive me working with old bikes this will be quite satisfactory IF THE OIL STOPS LEAKING, if not get a new box.
Dave GS

 

[ianboydsnr]

What about jointing compound around the bolt threads, it is not pressurised
so have a go. And a belvel box is NOT a diff.
dave GS.

I knew that, and the choke is not a choke, but who cares

 

[mylovelyhorse]

is it abs or non abs?

Non ABS

I have a spare non abs r1150r diff, that I could probably loan for a few months

Thank you very much, a most kind offer. I have, however, decided that i shall go for a 2nd hand replacement ASAP.

 

[mylovelyhorse]

I have asked about this on the BMW-tech list and here's what I have had in reply from a chap that really knows his onions:

"The crownwheel assembly is made of an aluminum center hub with a steel gear and stub axle where the wheel attaches.The aluminum hub is pressed ino the steel gear. The bolt holes go all the way through the steel part, and the aluminum is visible throught the center hole as well as through the bolt holes.

"If the press fit between the hub and gear loosens. oil can pass. At that point, the connection will loosen further, leading to gear tooth misalignment adn gear failure.

"I believe that the problem is brought about by mis-shimming at the crownwheel bearing. When that bearing fails and the seal leaks, that is a signal that the SHIMMING needs to be corrected, as well as the bearing and seal replaced. I hear of many people who just install a new bearing with the old shimming. This is a mistake.

"BMW has had many rear drive failures. I would venture a bold statement that the ENTIRE root cause of the problem is incorrect shimming. It is not" Bad bearings, bad seals, wrong oil, overloading, etc.

"Sadly, many BMW dealership mechanics do not understand how to correctly shim the paralever rear drive."

So it looks like not re-shimming when I replaced the bearing, plus the use of a press to get the new bearing on may be the root cause of my issue. My fault then. Ah well, it's a shallow learning curve but I'm moving along it slowly but surely

Cheers

 

[davegs]

Bevel box

Ah well looks lioke another box wtd, don't worry too much yiou'll get a s/h one for £150 or less. Thats what I paid for mine now done 40000 with no probs give Mr S. a ring and see if he can help.
Dave GS.

 

[Bronco Billy]

Have a word with Steve Scriminger of Scriminger Engineering. If he cant fix the problem then he will advise you of the best way forward.....

 

[mylovelyhorse]

give Mr S. a ring and see if he can help.

I've just done that. He said that he's never seen that go before and so doesn't know if it can be repaired.

I have a dread of finding that it needs repair after repair and I end up spending more money and time trying to resolve this than is sensible.

 

[mylovelyhorse]

Have a word with Steve Scriminger of Scriminger Engineering. If he cant fix the problem then he will advise you of the best way forward.....

Well you beauty

Knows the problem, knows how to fix it, has the required parts.

Thank you very much indeed for recommending him

 

[bumpmuncher]

"The crownwheel assembly is made of an aluminum center hub with a steel gear and stub axle where the wheel attaches.The aluminum hub is pressed ino the steel gear. The bolt holes go all the way through the steel part, and the aluminum is visible throught the center hole as well as through the bolt holes.

"If the press fit between the hub and gear loosens. oil can pass. At that point, the connection will loosen further, leading to gear tooth misalignment adn gear failure.

"I believe that the problem is brought about by mis-shimming at the crownwheel bearing. When that bearing fails and the seal leaks, that is a signal that the SHIMMING needs to be corrected, as well as the bearing and seal replaced. I hear of many people who just install a new bearing with the old shimming. This is a mistake.


Cheers

that is what i found with mine (pictures in the thread of the hub and pinion) and how jim cray described it. he also said it would be in excess of £400 to rebuild it with new bearings seals and it would possibly need a new pinon and crown wheel. out of interest what was scrimingers rough quote

 

[Bronco Billy]

Well you beauty

Knows the problem, knows how to fix it, has the required parts.

Thank you very much indeed for recommending him

No problem mate. Steve Scriminger is a top engineer who specialises in BMW bikes. The thing is though is that he is prepared to take the time and trouble to talk to people and give them the benefit of his hard won experience. Just dont keep him talking too long cos it keeps him away from fixing our bikes...

 

[CHANGELING]

Sooooo... did this issue get fixed 'cos guess what I found leaking out from my wheel bolt holes today...

And Hungary is not the place to be when this happens I can assure you.

 

[dancata]

Sooooo... did this issue get fixed 'cos guess what I found leaking out from my wheel bolt holes today...

And Hungary is not the place to be when this happens I can assure you.

Maybe grease melting from the bolts from a previous wheel removal?



If you need anything, come to Cluj, Ro, it's not far from Hungary

 

[mylovelyhorse]

Sooooo... did this issue get fixed 'cos guess what I found leaking out from my wheel bolt holes today...

Oh dear. Mine required two visits to scrimingers and the costs went to the same area as a 2nd hand FD from Motorworks but they did get fixed.

And Hungary is not the place to be when this happens I can assure you.

Cripes!

 

[CHANGELING]

I would love to know exactly what they did so maybe could find an engineer here to do the same. The shipping costs to the UK for a final drive don't bear thinking about!

Maybe I will Dancata if I can get this bike fixed once and for all.

 

[mylovelyhorse]

I would love to know exactly what they did so maybe could find an engineer here to do the same.

He replaced the bearings and crown from the crown & gear, re-shimmed & set up the FD again. Parts could be your problem...