• Welcome, Guest! We hope you enjoy the excellent technical knowledge, event information and discussions that the BMW MOA forum provides. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please click the 'Log in' button above and enter your BMW MOA username and password.

    If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the discounts and benefits the BMW MOA offers?

1987 K100RS- Hard Downshifting

tmwkicker

New member
I've got a 1987 K100RS with just under 31,000 miles on it.

While riding tonight, I noticed that my downshifts were getting a little rough. What I mean by this is that it was getting a little harder to push the shift lever down to move from gear to gear. Before tonight, if I simply placed my foot on the top of the shift lever and pulled in the clutch, the weight of my leg would cause the downshift. While riding tonight, I had to actually apply downward force to the lever before it would engage the next lower gear. The clutch felt no different, nor did the feeling of an upshift.

Does anyone have any thoughts that may help me? Is this something I should be worried about?
 
I'll second Lee's thought. That's the classic symptom of dry clutch splines.. It's a biggish job, but not rocket science, and many home wrenches have managed to DIY. Plan on it being a half-hour job*

Half-hour job = at least ALL day. Possibly more, depends on what breaks, and how long it takes to get a replacement. I got really good at spline lubes at one point (don't ask why, it wasn't a good thing..) and got it down to 45 minutes with two of us (both somewhat decent wrenches) working on it, on a lift in a garage with all the right tools. That said - for the first time, don't make it when you NEED the bike. Plan on at least a 1 day job.
 
I just did mine recently. It took me about three and a half hours...but I had done it before....or more correctly I hadn't done it well enough before which is why I was doing it again.:banghead

My minimal lube job lasted about 1.5 years until downshifting became very difficult. One thing I noticed was that if I pulled in the clutch and waited a second or two it would shift like normal; especially if I gave the motor a little bump while the clutch was pulled.

This should work as a check to verify dry splines are your issue.
 
Thank you all, for your help.

When performing the clutch spline lube, what lube did you use? In reading about the process and watching Chris Harris' videos on YouTube on the issue, the Staburags paste is called for those splines.

Have you guys tried anything else that is more readily available than the Staburags?
 
Being that far in you should go for the clutch nut o-ring. It also gives you a chance to look at how much clutch you have left.
Jeff
 
Being that far in you should go for the clutch nut o-ring. It also gives you a chance to look at how much clutch you have left.
Jeff
IMHO - only if there are indications of a leak. It is much more of a job to get to the nut and O-ring.. and you need some way of aligning the clutch plate when reassembling. It takes a 45 minute job to about 1.5 hours (using the same scale as above..)
 
AND you need to be absolutely positive that the clutch housing (flywheel), and the two pressure plates remain in the same relative rotational position to each other or you will end up with a vibration. The three pieces are not individually perfectly balanced. They are balanced to a tolerance with the light/heavy spot (don't remember which) marked. The three marks are supposed to be aligned 120 degrees apart for the best balance. The problem is that the factory marks disappear so you must mark the relationship BEFORE you disassemble.

Clutch discs on these bikes easily go way over 100,000 miles unless abused or contaminated.


:dance:dance:dance
 
AND you need to be absolutely positive that the clutch housing (flywheel), and the two pressure plates remain in the same relative rotational position to each other or you will end up with a vibration. The three pieces are not individually perfectly balanced. They are balanced to a tolerance with the light/heavy spot (don't remember which) marked. The three marks are supposed to be aligned 120 degrees apart for the best balance. The problem is that the factory marks disappear so you must mark the relationship BEFORE you disassemble.

Unless it's leaking, probably not worth all the extra work.

Clutch discs on these bikes easily go way over 100,000 miles unless abused or contaminated.


:dance:dance:dance
 
Thanks again, everyone, for your input.

I was able to do the clutch spline lube without any hitches. I had to replace the original clutch arm boot on the backside of the transmission, but that was it!

The splines themselves were pretty dry, but in good shape. I rode it yesterday and all seems good. Smooth upshifting and downshifting.
 
Back
Top