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Huh??

M

mgalie

Guest
Ok, folks. I'm not sure what the problem is, but I do know what it's like.

It's as if the clutch cable grew.

Suffered the dreaded clutch spline failure on my K75s and installed a new transmission.

After installation, I cannot adjust my clutch.

http://www.ibmwr.org/ktech/sidestand-clutch-adjust.shtml
As per, ibmwr, I set the exposed cable length to 75mm, but it's just way too much slack. I've set the trans end screw to both extremes (and some points in the middle), to no avail. Squeezing the clutch grip just send the barrel at the trans slipping off the fork.

I am completely baffled.

What could cause such a thing and how to fix it?
 
Ok, folks. I'm not sure what the problem is, but I do know what it's like.

It's as if the clutch cable grew.

Suffered the dreaded clutch spline failure on my K75s and installed a new transmission.

After installation, I cannot adjust my clutch.

http://www.ibmwr.org/ktech/sidestand-clutch-adjust.shtml
As per, ibmwr, I set the exposed cable length to 75mm, but it's just way too much slack. I've set the trans end screw to both extremes (and some points in the middle), to no avail. Squeezing the clutch grip just send the barrel at the trans slipping off the fork.

I am completely baffled.

What could cause such a thing and how to fix it?


Dumb question but... are you sure that the cable end is properly seated in the swing arm housing. I.e. The ball end on the cable housing is not below the housing.
Don't ask me how I know this can be a problem:banghead
 
No, just checked; it's definitely seated. The cable just has waaay too much slack (even with the swing arm resting on the muffler) and there isn't much room left on the adjuster up by the grips.

Getting the cable off the swing arm should involve prying the swing arm up and some grunting, but it's just like swatting a fly.

The cure would be a shorter cable, but what the heck changed from two weeks ago when it worked? Sure, new trans, new swing arm, but that shouldn't change anything relevant. :scratch
 
Darn good question. Did you remember to install the clutch push rod? If you swapped trannies was this possibly missing. I am just looking at the more obvious possibilities and will let the experts help you get it fixed.

I have been told that on the K75 this pushrod is installed from the engine side of the tranny.
 
You're right, the K75 push rods come out of from the engine side. The new tranny had a different style rod, so I swapped it along with the ball bearings, pressure piston and bush (PN 14) from the old tranny.
The K75 pushrod has a shoulder at the clutch end that the K100 doesn't. The shoulder is what prevents it from being removed from the rear of the transmission. Since this is a K75 - hopefully the pushrod with the shoulder was used (and the shoulder is what pushes on the clutch spring, and sets the release position.)
One concern I had was I wasn't sure if I had tapped #14 onto the rod far enough, but it's hard to know when the clutch cable is too slack to pull the fork up.

http://www.realoem.com/bmw/showparts.do?model=0572&mospid=47908&btnr=21_0074&hg=21&fg=10
Your comment on #14 is a puzzle to me.

IIRC the step on that end of the pushrod is a machined section of the rod.. #14 appears to be simply a bushing the bearing runs against. It shouldn't need tapping on I believe.. it should slide down to the shoulder on the rod (don't have a rod here to look at - so this is by old memory.. - which means I could be remembering wrong.. it's been a while since I had one apart..)
 
The K75 pushrod has a shoulder at the clutch end that the K100 doesn't. ..... Your comment on #14 is a puzzle to me.

Right about the shoulder at the clutch end; the new trans didn't have this, so it must have been from a K100.

As to #14, on the K75 at least, it is a separate piece. To get the push rod out of a K75, you need to punch the rod through #14. Thus, to reinstall the rod, #14 needs to be tapped back on.

Because the rod comes out of the back on a K100, this isn't necessary, but it looks like it comes off. Haven't tried yet, though.
 
Oh - one more question..

Since you replaced the transmission, can we also assume you replaced the clutch disk?

If so - you did remember to install the large metal ring under the OD of the diaphram spring before putting the pressure plate on? If that was missing, or on the wrong side - that would account for excessive play..

PN-2 in http://www.realoem.com/bmw/showparts.do?model=0572&mospid=47908&btnr=21_0073&hg=21&fg=05

Indeed, the wire ring is in there.

The issue I'm having is strictly with the cable, though (so it seems to me). The swing arm is at the furthest point it could be, and there is just way too much slack on the cable for it to lift the arm.
 
Indeed, the wire ring is in there.

The issue I'm having is strictly with the cable, though (so it seems to me). The swing arm is at the furthest point it could be, and there is just way too much slack on the cable for it to lift the arm.
And the ring is between the clutch housing and the spring?

A question.. if you try to operate the clutch using the lever on the back of the transmission - how does it feel?

I can't imagine a scenerio where the clutch cable grew that much without breaking.. but I supose I haven't imagined everything :) A new cable would put that concern to bed..
 
And the ring is between the clutch housing and the spring?

A question.. if you try to operate the clutch using the lever on the back of the transmission - how does it feel?

I can't imagine a scenerio where the clutch cable grew that much without breaking.. but I supose I haven't imagined everything :) A new cable would put that concern to bed..

The metal ring is in place.

It's hard to describe how the lever feels from memory. I'll have to get back to you on that when I'm near the bike.

I guess it's off to the dealer tomorrow for a new cable, but like you said, it's difficult to imagine it stretching so much without breaking. Especially since it's been out of use for two weeks. hmmmm


Thanks,
Mike
 
The brick flies again!

Well, all is in order with the new clutch cable! Have been out putting around the past two days. I still have some lingering concern about just what happened to the old cable (it's not obviously broken), but I'm just happy to have personal motorized transport again!

Thanks everyone for all the advice!
 
Mike - that's a new one for me. The cable had to be coming apart in the center for this to happen. If you're really curious - cut one end off and pull it out. Doggone mystery!
 
Will do!

I compared the new cable to the old one, and the old one does appear to be longer. Will have to pull the old one tight, though, to find out.
 
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