Boxerworks.com

I have a 1979 R65 with 30,000 miles on it. Ever since I got it 4 years ago at 11,000 miles, it has had a jerky clutch. I put an EZ-clutch on it and it has been usable, but it still has a very short friction range. From the time the clutch starts to engage to fully locked up is only a ¼ inch of lever movement.

Now something new has happened. On a very cold day I went for a ride. Heading up the first hill out of the neighborhood, the clutch started slipping. I stayed off the power for a few miles and I tried pushing it again and it would not slip. On the way home from work, it did the same thing. This time I noticed there was no slack in the clutch adjustment and I corrected that.

It was not slipping under load after a few miles, and there was an 1/8th inch of slack in the cable, but if I pulled even the slightest amount on the clutch, it would slip.

Why would a cold clutch slip and stop slipping when it warms up a little.

Do I need a new clutch? Do I need other stuff down there like plates?

Thanks

Have you done a spline lube? That might not explain totally the slipping but the jerkiness could be that the clutch plate is not sliding smoothly on the input shaft. Probably need to get in there and clean out all of the grit and put on a slight amount of Honda Moly paste.

Kurt in S.A.

Kurt in S.A. wrote:Have you done a spline lube? Kurt in S.A.

I pulled the transmission in March of 07. It was not dry, but I added grease then. I will pull it again and check that.

bbelk wrote:

Kurt in S.A. wrote:Have you done a spline lube? Kurt in S.A.

I pulled the transmission in March of 07. It was not dry, but I added grease then. I will pull it again and check that.

Hmmm, but your clutch has been jerky from the get go. You greased the splines in March of 07, and if I understand correctly it was still jerky afterwards. So I wouldn't be inclined to pull the transmission to grease the splines again.

But it's really a moot point, isn't it. Aside from the jerkiness you have the new problem of the clutch slipping under some conditions--when it shouldn't slip under any condition. So you're going to have to pull the transmission anyhow. Unless somebody can come up with an idea that you can do externally to deal with the clutch slipping problem. I wouldn't hold my breath though.

Well, on the positive side, you sure do get a lot of good practice working on airheads. Got heat in your work area? Working on an airhead in a cozy shop when it's cold outside--instead of working on the house ad infinitum, has its good points I would think.


Ken

Clutch disk in the right way round?
How do the pivot points at the lever on the transmission look? Any play or slop?
Sometimes the pin will work itself out halfway.

When you had the transmission out, did you check the input shaft end play? You better.

Ken in Oklahoma wrote: Working on an airhead in a cozy shop when it's cold outside--instead of working on the house ad infinitum, has its good points I would think.


Ken

Indeed!

The lift is under a roof with walls on two sides. That’s enough cozyness for Austin. It was 24 this morning, but its up to 60 something now.

mattcfish wrote:Clutch plate in the right way round?
How do the pivot points at the lever on the transmission look? Any play or slop?
Sometimes the pin will work itself out halfway.

I doubt if the clutch has ever been removed as the bike only had 11,000 miles on it when I got it and I have not had it off. I suppose the factory could have put it in backwards. I am not sure how I will tell.

The pivot pin looks good from the outside.

Duane Ausherman wrote:When you had the transmission out, did you check the input shaft end play? You better.

When I first got the bike, in the days of the old Boxerworks forum, I posted about the jerky clutch. The input shaft end play came up then and has been on my list of things to check. The most popular opinion was that the splines needed greasing and I was able to do that without removing the transmission completly from the bike, so I never checked the end play and have regreted it since.

I guess I should get started now.

bbelk wrote:

Duane Ausherman wrote:When you had the transmission out, did you check the input shaft end play? You better.

When I first got the bike, in the days of the old Boxerworks forum, I posted about the jerky clutch. The input shaft end play came up then and has been on my list of things to check. The most popular opinion was that the splines needed greasing and I was able to do that without removing the transmission completly from the bike, so I never checked the end play and have regreted it since.

I guess I should get started now.

One thing I should mention, but not sure if it applies to your model: for removing the transmission, the factory manual says you have to remove the exhaust system etc and unbolt and move the engine forward to remove the transmission. On my /5 this was not necessary, on the /6 all I had to remove was the front engine mount stud to tilt the engine forward a bit, the clutch actuating lever from the back of the transmission, and the battery box as well. The transmission came out with no problem. I would try this first before following the factory manual to the letter.