My "friction zone" is more like a friction point

[gossamerjohn]

Hi all.

My bike has a very VERY small friction zone. The zone translates to about 1/2" or so at the clutch lever on the handle bars. Basically, the last bit of the lever before it's back in it's resting position is all the clutch engagement there is.

My previous not-BMW bike had a much larger friction zone, at least half of the clutch lever movement was friction zone.

Otherwise, there are no symptoms of the clutch going bad. No slippage, no notchiness from the splines, no grinding, noise, none of that.

I set the clutch lever at the back of the gear box so that it's as close to parallel to the gear box cover (per Duane Auscherman's site) as possible.

Also, the clutch lever adjusting bolt is backed out as far as I can get it without it being totally loose. (at the gear box)

So, do I need to replace/rebuild the clutch? Never done it before, is this something I can probably do myself?

[manicmechanic]

Depends on how adept you are. There's something in your description that says splines, but I can't quite put my finger on it.

[gossamerjohn]

Splines: I was wondering the same thing. Maybe lube the splines first and see if that helps?

I'm fairly adept if I have a set of instructions, mostly because I take it slow and try not to do anything stupid.

I've rebuilt forks, replaced steering complete head bearings, rebuilt carbs.

[rpeckham136133]

Hi all.


I set the clutch lever at the back of the gear box so that it's as close to parallel to the gear box cover (per Duane Auscherman's site) as possible.

Also, the clutch lever adjusting bolt is backed out as far as I can get it without it being totally loose. (at the gear box)



Not really understanding that "close to parallel" stuff. Before you even think about getting into the clutch, try different adjustments.

What you want to do is this: 1. turn the adjustment screw at the perch all the way IN. This should give the max amount of cable at the other end. 2. Adjust the lever at the clutch end (i.e. turn the screw, then tighten the locknut) so that there is just a little bit of slack left. That screw does a lot with just one turn, so pay attention. You are trying to not have anything tight. 3. Go back to the clutch lever and start to squeeze it: what you want is to have about 1/2" free movement before you encounter any pressure. Adjust by turning OUT the nut at the perch (this takes up the slack that you left at the other end) This allows a fine tuning after the gross tuning was done by the screw at the clutch end. Once you have just a little slack left when you first pull the clutch lever, you will have adjusted the clutch correctly.

It is the nature of these clutches to engage pretty quickly. Though the /6 clutch has a lot more "zone" than my /2 clutch. As long as you are hearing and feeling no grinding, slipping, etc, I would not get into the clutch. If you have a bad throwout bearing you will probably feel it through the clutch lever, and hear a rumbly grindy kind of noise. A bad clutch itself will usually just slip under load, usually in the higher gears when trying to accelerate. Lubing splines will not fix anything, in and of itself.......

Try the adjustment. You might be surprised.

[AntonLargiader]

Original clutch? Replace it. The lining material is probably rock-hard.

While you're there, check the crankshaft endplay and the input shaft end play. Excessive amounts of either will make for a grabby clutch also.

[20774]

I set the clutch lever at the back of the gear box so that it's as close to parallel to the gear box cover (per Duane Auscherman's site) as possible.

The clutch lever at the back of the tranny should be parallel to the gear box cover when you have pulled the hand lever about half way. Not sure from your description if that's what you mean. I'm sure Duane described things correctly...

[rocketman]

The clutch lever at the back of the tranny should be parallel to the gear box cover when you have pulled the hand lever about half way. Not sure from your description if that's what you mean. I'm sure Duane described things correctly...

I think he's talking about with it at rest with no action on the lever, that is the way that Duane showed in his tech session at the Festival of fives some years ago and the way many i have met do it and how I have myself.

RM

[sumran]

There is a thin needle cage bearing between the piston and the washer in the clutch control assembly.

http://www.maxbmwmotorcycles.com/fiche/MainDiagrams.asp?mospid=47841

If that assembly was taken apart and the bearing fell out or it was left out during reassembly, the clutch will work, but it uses up all the adjustment and it works like what you describe. Don't ask me how I know this. Let's just say you might find the bearing on the driveway where you were cleaning the transmission case while you were doing a spline lube.:blush Obviously it would cause problem to ride it that way for long time. It might be worth checking if the bike is new to you or has been apart recently. A previous owner might have left it out.

[BobZ]

Lots of great ideas here, but all the airheads I've ridden have had clutch action that was pretty much an on-and-off switch. Just be sure the required clearance at the lever is present.

[gossamerjohn]

Bob Z.

That is exactly what my BMW dealer mechanics told me. They checked it and said it was fine.

Thanks for the input, confirming everything is a help.

[bcgilligan]

My old GS is on clutch #2 at 115,000 miles and it feels solid .... no slippage in top gears at full throttle. It was installed at 70K. There was never much of a take up zone on this bike's clutch, just a very narrow band between no engage/total engage. Seems like the killer to these clutchs is when the rear main seal decides to blow. I have an idea that if my rear main didn't leak, I may have still been riding on the original.

Bob