Author Topic: Transmission Problem or Just clutch?  (Read 1009 times)

Offline Laitch

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Re: Transmission Problem or Just clutch?
« Reply #25 on: November 15, 2021, 11:33:54 PM »
And should I pick up a second set of those locating pins for mating the transmission? It has two already but would there be a benefit for adding another set?
There will be no benefit installing a second set of dowels for that pupose. It would be good to know if the intermediate housing-to-engine dowels are installed. BMW recommends replacing the clutch nut, the compression ring, the output shaft o-ring, the clutch pack screws and their washers when reassembling the clutch. Some members here do; some don't.

I suggest you use a clutch alignment tool during re-installation of the clutch pack, given that the clutch plate hub splines were damaged. Use this video for guidance; alignment instructions start at 4:13.
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Offline frankenduck

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Re: Transmission Problem or Just clutch?
« Reply #26 on: November 16, 2021, 05:56:45 AM »
BMW recommends replacing the clutch nut, the compression ring, the output shaft o-ring, the clutch pack screws and their washers when reassembling the clutch.

Where does BMW recommend this? Only a new O-ring is mentioned in the clutch chapter of the service manual.
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Offline The Mighty Gryphon

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Re: Transmission Problem or Just clutch?
« Reply #27 on: November 16, 2021, 09:04:25 AM »
Where does BMW recommend this? Only a new O-ring is mentioned in the clutch chapter of the service manual.

I haven't noticed if there is mention of it in the factory service manual, but I seem to recall replacement is mentioned in the Clymer manual.  I do know there are notes in MaxBMW's official parts fiche that recommend replacing the parts Laitch mentions.  Maybe it's just a way to sell extra parts for a maintenance job.

I can report that I have rebuilt the clutch on a couple bikes without replacing the clutch nut and bolts and had no ill effects.  However, I have a handful of clutch o-rings and always replace it when I'm in there.  I think that the clutch basket bolts are stretch bolts and can't be restretched or something like that.  I just put a little BLUE Loctite on them when I put them back together to guarantee that they won't loosen up.
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Offline Laitch

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Re: Transmission Problem or Just clutch?
« Reply #28 on: November 16, 2021, 10:50:03 AM »
Where does BMW recommend this? Only a new O-ring is mentioned in the clutch chapter of the service manual.
If we can agree that authorized BMW dealerships that sell BMW motorcycles and service accurately represent BMW's intentions, then these recommendations can be found in BMW's parts fiches, specifically in this case, MaxBMW's parts fiche.


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I wept because I had no radials until I met a man who had no splines.
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Offline frankenduck

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Re: Transmission Problem or Just clutch?
« Reply #29 on: November 16, 2021, 12:56:58 PM »
If we can agree that authorized BMW dealerships that sell BMW motorcycles and service accurately represent BMW's intentions, then these recommendations can be found in BMW's parts fiches, specifically in this case, MaxBMW's parts fiche.

They probably got that from the Clymer manual. :laughing4-giggles:

Those notes are added by MAX(they also add comments for other parts) and are not part of the BMW fiche.

The Haynes manual refers to a "new" clutch nut but makes no mention of new for the compression ring or the other six nuts/washers.

In looking at the BMW K1100 manual it DOES indicate a new O-ring is used (obvious) and that the clutch nut should be "renewed" but not any other clutch parts.

I was just curious if anyone had ever seen anything about this from Der Fatherland, such as in a manual or technical service bulletin.


My shade-tree mechanic opinion: (I studied materials science when getting my civil engineering degree so I'm not a complete idiot when it comes to metals.)

1 - Replacing the O-ring is a no-brainer. I use Viton O-rings since they last longer than rubber.

2 - Probably a good idea to replace the clutch nut since the K1100 manual does call that out. (I've re-used them many times without issue however.)

3- Compression ring: Meh, probably OK to re-use it.

4 - All the six outer bolts do is hold the clutch pressure plates together so I can't see any good reason why those would need to be replaced.

5 - Replacing the external lock washers for those six bolts might make sense but it's probably not the end of the world if you do re-use those. I've re-used them without issue.

Finally, it's just a motorcycle, not the space shuttle where material properties and tolerances make a "real" difference.
Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
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Offline Laitch

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Re: Transmission Problem or Just clutch?
« Reply #30 on: November 16, 2021, 02:26:48 PM »
Those notes are added by MAX(they also add comments for other parts) and are not part of the BMW fiche.
My shade-tree mechanic opinion:(I studied materials science when getting my civil engineering degree so I'm not a complete idiot when it comes to metals.)
Finally, it's just a motorcycle, not the space shuttle where material properties and tolerances make a "real" difference.
The notes in Max's fiche could possibly be the result of experience working on thousands of motorcycles in a well-lighted building rather than several under a shade tree; however, they also could be bald-face attempts to expand their wealth through the sale of costly fasteners and other parts.  Regardless, perfection is illusive everywhere.  177381

Secondly, nobody here is claiming any idiocy that may have been evinced in this thread is complete.  :laughing4-giggles:

Finally, a motorcycle is certainly not the space shuttle, but the rider of an aging motorcycle is likely exposed to a much higher chance of being maimed or dying as a result of mechanical failure than a rocket-riding space shuttle astronaut partly because rocket scientists tend to be particular about the quality and condition of parts in a rocket's assembly while the Brick's rider might be conserving money by assembling with used parts of unknown condition, or parts of uncertain quality.

Risk-taking is part of riding's allure.  112350
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Offline frankenduck

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Re: Transmission Problem or Just clutch?
« Reply #31 on: November 16, 2021, 03:33:25 PM »
I'm much more afraid of deer than anything else when I ride. I never worry about what nuts and bolts I used to put the clutch together.
Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
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Offline Laitch

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Re: Transmission Problem or Just clutch?
« Reply #32 on: November 16, 2021, 05:21:03 PM »
I'm much more afraid of deer than anything else when I ride. I never worry about what nuts and bolts I used to put the clutch together.
That's what they all say.  :laughing4-giggles: 
  • Along the Ridley in Vermont.
  • 1995 K75 80,000 miles
I wept because I had no radials until I met a man who had no splines.
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Offline The Mighty Gryphon

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Re: Transmission Problem or Just clutch?
« Reply #33 on: November 16, 2021, 07:49:08 PM »
Being a cheap bastard, I usually need a very good reason to replace what appear to be good parts, especially passive items like fasteners.  With the torque that is applied to the clutch hub nut, the concern would be galling of the threads.  I always check them closely before reusing that nut.  I have one here at the ready just in case I need it.

The screws that hold the housing together are not torqued to extremes and do not operate under a lot of tension, so my only concern would be loosening.  Fortunately, that can be prevented by proper torque and a drop of blue Loctite along with the lock washer.  Like I mentioned above, the o-ring is cheap and prevents more expensive problems, so if I'm in there I will change it.  I have several in my tool box so there is no barrier to getting it done.
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Offline bornfrustrated

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Re: Transmission Problem or Just clutch?
« Reply #34 on: November 19, 2021, 01:24:26 PM »
So friction disc, clutch nut, and the o ring behind the clutch nut. I may also do the bolts holding the housing together since the lock washers on them are pretty beat. What's the most convenient place to get these that I won't spend an arm and a leg? I know I can get them from tills.de, but $40 in shipping is nuts. Does anyone have the Sachs clutch part number so I can see if I can find it in the us?

And moly paste too. Honda moly 60 is common?
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Offline Laitch

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Re: Transmission Problem or Just clutch?
« Reply #35 on: November 19, 2021, 03:19:33 PM »
What is convenient for me is MaxBMW. There is no need to go overseas on a search for these parts. Do a search here and you'll find alternatives.
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Offline bornfrustrated

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Re: Transmission Problem or Just clutch?
« Reply #36 on: November 22, 2021, 06:18:05 PM »
I'm having trouble finding the Honda moly for the input shaft. Any suggestion on an alternative? And clarification the viton o ring is the 19x4 o ring behind the clutch nut? Also, Do the splines of the clutch basket need lubing?
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Offline Martin

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Re: Transmission Problem or Just clutch?
« Reply #37 on: November 25, 2021, 12:56:15 AM »
Honda 60 has been replaced by Honda M77. A Honda should be able to order it in for you.
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Offline Scott_

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Re: Transmission Problem or Just clutch?
« Reply #38 on: November 25, 2021, 07:56:28 AM »
Honda 60 has been replaced by Honda M77. A Honda should be able to order it in for you.
Regards Martin.
I'd be cautious of the M77, as it is not up to the the same compound quality(composition) as the M60....
If you do a google search for the Honda Moly 60 you should come up with some older threads(from 2006...) discussing this very issue.
They discussed the chemical makeup of the two and the consensus of the experienced mechanics and riders is that the M77 is no better than what you buy from BMW.
The 77 has a lower melting temperature than the 60 and less molly in it. Even the Honda service techs don't use it for the same service procedures anymore.(used less often).
The most common suggested replacement was the GD525, however Guard Dog is no longer in business anymore either.... sad.

Here's one discussion:
https://forums.bmwmoa.org/showthread.php?78215-ATTENTION!!!-All-K-bikes-HONDA-MOLY-60-DISCONTINUED


YMMV, do your own research, after all, this is the internet..... and we all know what that means.
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Offline frankenduck

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Re: Transmission Problem or Just clutch?
« Reply #39 on: November 25, 2021, 09:56:48 AM »
Ted Porter sells spline lube.  I've never used it but TP is a good place for BMW stuff so I assume that this stuff is good:

https://www.beemershop.com/product/ts-60-spline-lube.html
Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
New to K bikes? Click here.
K Bike Maintenance & Mods: Click here.
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