[BadMonk]

Had the bike (2007 Vegas) to a dyno tuner last week. At the end of the runs, he said the clutch was slipping. I finally got the chance to take a closer look at the assembly and found that the clutch pinion gear does this...

When I move it by hand, it feels like it's rolling over the first two or three gear teeth...and I don't it should have that kind of play/slop in it. Am I right?

 

[tree1979]

Its going to have some play. Doesn't look like its excessive to me. How many miles to you have on the bike?

 

[WHITE_VIC]

Looks normal to me

 

[BadMonk]

Under 20K. New clutch plates about 4K miles ago.
When the tuner said the clutch was slipping, it led me to the pinion. The pinion wouldn't fully extend when letting go of the lever. See the video below.

 

[BadMonk]

Under 20K miles on odo. New clutch plates about 4K miles ago.

When the tuner said the clutch was slipping, i noticed the pinion would not fully extend when letting go of the lever. That's can't be normal ... it only extends when I manually move it back to position. When I move it by hand back to position, something thunks against the inside of the primary cover.

 

[BadMonk]

By the way, it's a hydraulic clutch. The slave cylinder's actuator rod isn't bent. When removed from the pinion, it has full range of motion and moves smoothly. The pinion gear, on the other hand, will not return to normal position on its own. So there's something going on with the clutch or pinion or something (but not the slave).

 

[tree1979]

When was the last time the fluid was changed in the clutch lever master cylinder? May be too full as well. One reason I won't have a hydraulic clutch. Not adjustable enough.

 

[Trout]

In your first vid it appears to work normally.
In the 2nd vid with the cable hooked up it does not return all the way.

Any adjustment on the cable or slave to get a bit more slack?

 

[BadMonk]

Fluid is clear. Most likely changed last year. Fluids get maintained every two years. But...too much fluid in the master can cause a problem?? I didn't know that. When I move the pinion by hand, I hear a short air popping sound in the master...that had me look at the master and thinking it was overfilled. You may be onto something.

 

[Trout]

Do YOU feel any slippage?

Coming off the line normally or under hard acceleration?

How about a third gear run: hold it at 2500 rpm then go wide open: Slip?
Try it again at 3000: Slip?
Again at 3500: Slip?

Why is the dyno guy saying it's slipping?

 

[tree1979]

When you pull the lever, it adds pressure, which withdraws the cable at the slave. If you have too much fluid, it causes excess pressure to begin with, especially if it heats up from use.

 

[tree1979]

If the pinion isn't rotating back by itself, then you have an issue with the clutch diaphragm spring. Its what pushes the pinion back out. Not likely to be the issue, but I guess it could happen. Definitely looks like something with the hydro clutch. If its been that way for too long, you probably have damaged the clutch plates and will need to replace them too.

 

[BadMonk]

You're right, Trout, in what you see in the vids. There's no adjustment on a hydraulic clutch.

I don't feel slippage under normal riding conditions but I hadn't whacked it WOT like the tuner did over and over again. If I did, then I'd feel slipping since the pinion won't return to normal position and holds the clutch in a slight feathering position.

Have to check fluid level. It may be overfilled.

 

[BadMonk]

Thanks tree. It sounds like you hit the nail on the head. I'll check into those issues that you mentioned and see what I come up with this weekend. Thanks again.

 

[tree1979]

Here is a pic of the pinion. Notice the splines at the bottom?

The splines connect to the rack (clouded below) and compress the spring to release pressure on the plates.
View attachment 499923

The diaphragm spring is the only thing that that counters the rotation applied by the clutch cable (standard or hydro).

 

[tree1979]

Thanks tree. It sounds like you hit the nail on the head. I'll check into those issues that you mentioned and see what I come up with this weekend. Thanks again.

No problem. Let us know how it works out!

 

[BadMonk]

Yeah, tree. It's the diaphragm spring that I wasn't sure about how that worked. It makes sense now that it's explained. I'm hoping that removing fluid gets it done. If not, I'll open it up and see what's what. Gotta get a new primary cover gasket first though.

 

[tree1979]

If the clutch was replaced 4k ago, you should have a newer gasket already. You can reuse them if you're careful. Then again, if you don't have one on hand to replace it if it gets damaged, you'll be in trouble. lol

 

[BadMonk]

My memory isn't the best any more but I have a good recollection of the primary cover and the magnetic strength. LOL!! Gasket should be good since it's kinda new but...like you said.

Just opened the master. Way overfilled. Saturday it'll go back together and see if less fluid does it. If not, then I'll be riding more of my '87 Goldwing for a while. Nothing in my world gets done fast

 

[BadMonk]

Here's the problem. A split pressure plate by Barnett. I installed it four or five years ago and don't believe they made HD plates at that time. Likely snapped while on the dyno.