Results 1 to 10 of 10

Thread: K100 clutch life

  1. #1
    Registered User
    Join Date
    Nov 2005
    Posts
    73

    K100 clutch life

    Hi All,

    As you guys may know from my other posts, I'm working to get the service on my new-to-me 85 K100RS updated. Next week I should get the Wurth 3000 lube ready to be mixed with Honda Moly 60 which from what I have seen is an acceptable alternative for the spline lube.

    My preoccupation is that if I'm going to get the transmission housing off to lube the clutch spline, instead of sliding the cover on 2 long bolts, should I just remove the cover completely, check the clutch and consider replace the disc. So far from the work I have done, it seems to me that the previous owner (who sold the bike on consignment, so I didn't get to meet him) did take good care of the bike up till 1999 then stopped using it. The bike has 32k miles on the odometer and I have no info to know if that is the true mileage.

    In case I need to pull the clutch, I got the alignment tool from Ken Lively of Polepenhollow Valve Tools and Clutch Pilots which is probably better than using mock up tool.

    I would love some feed back on whether I should take the plunge and check the clutch, or just slide the cover to lube the spline and put everything back. The bike shifts fine. The clutch level has the right amount of free play and engagement. So what are some of the life people are getting from their clutches.

    Thanks

  2. #2
    Registered User
    Join Date
    Apr 2012
    Location
    Los Angeles, CA
    Posts
    321
    My '87 K75 has 106K miles, and as best I can tell has never had the clutch replaced. It's running just fine. I can't imagine you'd need a clutch at 32K, unless you're actually seeing signs of failure.

  3. #3
    RK Ryder
    Join Date
    Sep 2005
    Location
    London, Ontario
    Posts
    2,044
    My '87 K100 needed the clutch replaced at 137,000 miles.
    Paul
    Retired and riding my RTs, the '87 K100 & the '98 R1100 !
    Treasurer of the Forest City Motorrad Club #159
    Knights of the Roundel #333

  4. #4
    Registered User
    Join Date
    Nov 2009
    Location
    Phila
    Posts
    50

    K100 Clutch Life, 146k miles on original, no wheelies or burnouts or timed 1/4 miles

    I bought my '85 K100RS with 37k miles, checked clutch thickness at 100K when I did the rear main seal, it had plenty of life left so I did not replace the clutch disk, just the single use nuts/bolts that you are supposed to change. Now have 146k miles without concern. My riding style allows for long clutch life, your mileage and previous owner's may vary.

    Is oil very slowly dripping out the weap hole under the trans? That meant rear main seal needed for me.

  5. #5
    Registered User
    Join Date
    Nov 2005
    Posts
    73
    Thank you all for the reply. I think I will just slide the cover to lube the clutch spline and not worry about the clutch then.

  6. #6
    Old man in the mountains osbornk's Avatar
    Join Date
    Feb 2006
    Location
    Marion VA-In the middle of some of the best riding in the country.
    Posts
    3,264
    Like brakes, the life if a clutch depends on the operator and how they ride. Some folks wear them out quickly but some old f*rts like me never wear them out.
    'You can say what you want about the South, but I almost never hear of anyone wanting to retire to the North.

  7. #7
    A bozo on the bus deilenberger's Avatar
    Join Date
    Mar 2003
    Location
    Spring Lake NJ, USA
    Posts
    7,711
    I would suggest that it still is a GOOD idea to completely remove the transmission rather then try sliding it back to lube the splines.

    The reason being - you want CLEAN splines to lube, and you want all traces of old and possibly incompatible old lube removed.

    It's also a good time to check the condition of the splines, and if there is any dribbling from the clutch-basket-nut O-ring, well - you've done 80% of the job so you might as well do the rest. Chances are about 100.1% that if the O-ring hasn't been changed in the past 4-5 years it is leaking (evidenced usually by a tiny drip from the drain hole in the bottom of the clutch housing.) They dry up and die with age, not so much mileage. Since you have the pilot tool, if you mark the clutch components so they go back in the same orientation, doing the clutch basket O ring isn't a big deal at all.. adds perhaps 1 hour to the job. You will need a large (seem to recall 32mm, but that's from memory) socket to remove the nut, and a decent torque wrench to re-tighten it (BMW wants the nut replaced whenever it's removed, but it is a split-locking nut, and a tiny bit of medium strength loctite will likely hold it in place just fine.)
    Don Eilenberger http://www.eilenberger.net
    Spring Lk Heights NJ NJ Shore BMW Riders New Sweden BMW Riders
    '07 R1200R (current ride) and some bimmers.. and a Porsche

  8. #8
    Registered User
    Join Date
    Nov 2005
    Posts
    73
    Quote Originally Posted by deilenberger View Post
    I would suggest that it still is a GOOD idea to completely remove the transmission rather then try sliding it back to lube the splines.

    The reason being - you want CLEAN splines to lube, and you want all traces of old and possibly incompatible old lube removed.

    It's also a good time to check the condition of the splines, and if there is any dribbling from the clutch-basket-nut O-ring, well - you've done 80% of the job so you might as well do the rest. Chances are about 100.1% that if the O-ring hasn't been changed in the past 4-5 years it is leaking (evidenced usually by a tiny drip from the drain hole in the bottom of the clutch housing.) They dry up and die with age, not so much mileage. Since you have the pilot tool, if you mark the clutch components so they go back in the same orientation, doing the clutch basket O ring isn't a big deal at all.. adds perhaps 1 hour to the job. You will need a large (seem to recall 32mm, but that's from memory) socket to remove the nut, and a decent torque wrench to re-tighten it (BMW wants the nut replaced whenever it's removed, but it is a split-locking nut, and a tiny bit of medium strength loctite will likely hold it in place just fine.)
    Thank you Don for the suggestion. The O ring, is it #11 on the pic?
    Attached Images Attached Images

  9. #9
    A bozo on the bus deilenberger's Avatar
    Join Date
    Mar 2003
    Location
    Spring Lake NJ, USA
    Posts
    7,711
    Quote Originally Posted by cy7878 View Post
    Thank you Don for the suggestion. The O ring, is it #11 on the pic?
    That's it. They ALL leak eventually. Luckily it doesn't seem to oil the clutch. It would be nice if it oiled the splines (and spared the friction surfaces) - but it just doesn't..

    BTW - and I really stress this - make certain to mark the clutch basket (1), the pressure plate (4) and the cover plate (6) relative to each other BEFORE disassembly. The assembly is factory balanced by spacing the light points as far as possible away from each other as they can be.. unfortunately the factory balance marks (of the light spot) are just a dab of yellow paint, often washed off when you clean the parts, and sometimes not there at all. If you use a center-punch, and mark each piece relative to the others (I do it in a line..) then the assembly marks will never go away and you won't end up with an imbalanced clutch assembly.
    Don Eilenberger http://www.eilenberger.net
    Spring Lk Heights NJ NJ Shore BMW Riders New Sweden BMW Riders
    '07 R1200R (current ride) and some bimmers.. and a Porsche

  10. #10
    Registered User
    Join Date
    Nov 2005
    Posts
    73
    So I'm down to the clutch housing. I need to get a socket to remove the M20 nut which Don mentioned may be a 32mm hex. I do have bunch of oil smear in the clutch housing, which now explains all the black dried up road grime I have at the side stand and gear box housing that took me 1 hour just to wipe off....

    Any thoughts on "oil resistant clutch plate" vs OEM BMW clutch plate? I took a measurement and I'm getting less than 5mm but barely over 4.5mm limit, so I think I'm going to just replace this since it's taking too long and I do not look forward to doing this again anytime soon.
    Attached Images Attached Images

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •