Rear Main Leak = Having to Buy New Clutch?

[Freelancer]

As the title asks, "Does oil contamination from a rear main leak mean that you have to buy a new clutch?".

I ask because my bike developed a rear main leak and the clutch has only 8k on it. The clutch does seem to slip a little right after I start riding but this quickly goes away. I'm about to order the rear main along with a few other parts and want to know if I have to shell out the $700 dealer price or "Can the clutch be decontaminated?".

Also would like to know if running 15w 50 could cause such leaks due to the oil being thinner than the 20w 50 recommended.

Any help appreciated,
Freelancer

[TIV]

If the clutch disk is soaked with oil I recommend changing it. Itīs very hard to, if not impossible, to clean it properly. You will also have to replace the six (I think) hexagon head bolts that hold the clutch together. They should only be used ones because they stretch when you torque them. I suppose here, that the pressure plate was replaced 8k ago to. If not, it could be a good idea to replace it with a new one.

Running a 15w - 50 does not cause the failure of the main seal. Itīs more likely that the cause is that some small particle, dust or something did it. Was the seal replaced when the clutch was overhauled 8kīs ago?

Itīs also worth mentioning, that you need a clutch centering tool if you are going to do this yourself.

[TimTyler]

All good suggestions.

... you need a clutch centering tool if you are going to do this yourself...

The tool is useful, but is not necessary. I've done the job twice using my eye and a #1 Phillips screwdriver (I cut the tip off) to line-up the clutch assembly.

[Freelancer]

Thanks for the input guys.

@TIV- Yes, the seal was "supposedly" changed at the same time ss the clutch. The rear main leaking was why the clutch was replaced. I am annoyed with there still being a leak after two trips to the shop. I've decided to either go to
a different mechanic or do it myself.
Only problems with doing myself are time and having a clean(not sitting in the dirt).


Next, question.

Has anyone tried the new "oil resistant" clutch plates from Siebenbrock?

Beemer Boneyard is selling these at a pretty steep $245. I cringe at the price but if it will keep me from buying an $800 oem clutch it might be justifiable.


What do you guys think/know?

Thanks,
Freelancer

[TIV]

I had this problem on a boxer (identical clutch) 20 years ago. Restored a R69S to mint condition and after two thousand miles  it started leaking. Took it apart, new main seal, and then rode it for about 20.000 miles. No problem. That bike is now in a museum.

I think what you have, is either a pure bad luck, or a bad mechanic. Everything has to be dead clean, and if I remember it correctly, it is very critical how the seal sits. You have to drive or press it in to exactly the right depth given in the manual. I remember ruining one seal because I drove it in to far. It can be a question of only 1 millimeter or so.

As for the centering tool I strongly recommend it. You can do it with a screwdriver or something, but if it is offset by only a small margin you can get vibrations. Itīs not that expensive anyway. I personally would forget about the "oil resistant" clutch plates from Siebenbrock and use the money for something else.

[frankenduck]

As for the centering tool I strongly recommend it. You can do it with a screwdriver or something, but if it is offset by only a small margin you can get vibrations.[/img]

This is simply not true.  The first time you pull in the clutch the clutch plate floats freely on the input splines.

[TimTyler]

As for the centering tool I strongly recommend it. You can do it with a screwdriver or something, but if it is offset by only a small margin you can get vibrations. Itīs not that expensive anyway.

Once the clutch housing is all back together and buttoned up, the clutch plate self-centers between the pressure plates the first time it spins.

The clutch tool merely enables you to line up all the pieces so that you can easily reassemble the housing properly.

[TIV]

As for the centering tool I strongly recommend it. You can do it with a screwdriver or something, but if it is offset by only a small margin you can get vibrations.[/img]

This is simply not true.  The first time you pull in the clutch the clutch plate floats freely on the input splines.

Sorry Freelancer, it was not my intention to give misleading information, my memory failed me. You are of course right frankenduck. The toolīs only purpose is to aid assembly. What got mixed up in my mind was that the clutch housing and the rear pressure plate are balanced at the factory and marked with paint. If the marks are not aligned you can get vibration. Other parts of the clutch are of course "floating"

[JamesInCA]

What is this $800 of which you speak? The OEM clutch plate appears to be $159.

[cy7878]

Hi James,

   I asked my dealer service guy when I was fearing a rear main seal leak.  He told me "need" to replace the clutch disc and the 2 pressure plates in the event of a oil contaminated clutch because the slippage causes burns to the mating surface and glazes the surface.  If I just replace the clutch friction disc, there is "a chance" that the 3 parts won't mate well and cause inconsistent clutch performance.   

The disc is $180.  The 2 sides add up to almost $600 to total about $800.  I have no actual experience replacing or not replacing the part. luckily my clutch was not oil contaminated and my leak was from the O-ring, so I stuffed everything back.  I look forward to see what others say.

[JamesInCA]

I've never replaced a clutch either. But you just described why I don't get service at dealers.

So many things "might" happen. And hence $160 becomes $800.  Plus labor.