Clutch Problems

[Doug D.]

Ok, so I'm pulling into my drive the other evening and I step on the clutch and nothing. I hit the brakes and kill the engine just short of ventilating the garage door. Luckily, I was only creeping up the drive or I would've had a real mess.

So the problem is this; Even with the clutch pedal fully depressed, the clutch remains engaged tight enough that I can push in the clutch and use the starter to move the bike around with the transaxle in gear (ignition turned off, of course ). My first guesses were that the clutch was out of adjustment, the throw out bearing was shot or the pressure plate had failed.

So I proceed as follows:

The trike has a hydraulic clutch. I checked the fluid level, this was ok. The fluid was a little dark, but didn't feel gritty. I pulled the motor and checked the travel of the slave cylinder. This is at about 1.25" at the top of the actuator arm, and about .625" at the mating surface of the throw out bearing. Spacing between the throw out bearing and the pressure plate calculates to be about .0625" with the clutch released. I'm told this is adequate enough to operate the clutch properly.

Next I check the throw out bearing itself. Same turns freely and smoothly, and shows a minimum of wear on the mating surface.

Next, I remove the pressure plate and clutch disc. The pressure plate looks like brand new, with no detectable wear on the mating surface. All the fingers are intact and evenly spaced, and none appear to be collapsed. The plate is heavy duty, and can't be compressed by hand, at least by me anyway. The disc is showing signs of wear, but is serviceable. The flywheel could stand to be turned, but is also serviceable.

Now the fun begins. Where I'm used to finding a bronze pilot bushing in the flywheel, I discover the remains of a needle bearing. The cage was all but disintegrated, and the needles were piled up in the recess. I also found the remains of some kind of felt-like seal, which is pretty much shredded. I haven't removed the flywheel to get a good look yet, but the race surface "feels" like it's in good shape.

Bear in mind, I've never changed a bug clutch before, but I've done dozens of 'em on American cars. I never saw a needle bearing in the flywheel before, and I'm told this clutch isn't stock but a heavy duty racing clutch. I was told the brand some time back, but don't recall.

In the past, whenever I encountered the problem I previously described, it was almost always a bad pressure plate and occasionally a throw out bearing. As all the components (with the exception of the needle bearing) appear to be ok, I'm at a stand still. In my mind, the bearing shouldn't prevent the clutch from disengaging. Any advice would be greatly appreciated.

Peace and ride safe!

[Gorilla]

I'm long out of the VW and the memory is not going back that far. But from what I remember you have found your problem. The throw out bearing if I remember is essential to clutch engagement. I think our experts will drop in here shortly

[DeathBySnuSnu]

The pilot bearing is a needle bearing with a seal to hold the grease in. Not the bronze like an old american car.
This bearing is in the big single bolt that hold the flywheel on. It is called a gland nut.
Get a new one and change it out. The only problem is it is large and torques to 265 ft lbs if i remember correctly. Unless you have a forged crank and nut like a hot rod stroker crank then around 400 ft lbs.

[Gorilla]

The pilot bearing is a needle bearing with a seal to hold the grease in. Not the bronze like an old american car.
This bearing is in the big single bolt that hold the flywheel on. It is called a gland nut.
Get a new one and change it out. The only problem is it is large and torques to 265 ft lbs if i remember correctly. Unless you have a forged crank and nut like a hot rod stroker crank then around 400 ft lbs.

I remember that nut now. I still have a socket that I bought to remove it with. Your right it was a son of a gun to break loose.

[Doug D.]

Thanks, guys! I appreciate the help. Looks like I'm buying a gland nut and throw out bearing tomorrow. I might even replace the disc since it's starting to show some wear, and have the flywheel turned as well. No sense in doing this twice when I already have it apart. I already have a socket that fits the gland nut. Not sure what I bought it for in the first place, but I'm glad I did.

Thanks again! Peace, and ride safe!

[Doug D.]

Turns out pieces of the pilot bearing got hung up in the pressure plate and kept it from releasing the clutch.

Thanks again for all your help!

[stinger608]

I'll tell ya a God send tool that I finally purchased a year or so ago:

http://carcraftstore.com/torquemultilplier.aspx

This specialty VW tool should be in every enthusiasts tool box! It uses a 7/16" socket and 25 foot pounds of torque to gain the 250 foot pounds on the gland nut.

It works on the 6 volt and 12 volt flywheels as well as the 4 bolt and 5 bolt drums for the axle nuts.

I used it putting my 1835 together and converting to disc brakes this last spring. I feel it paid for itself in that time line.

[Doug D.]

That's goin' on my Christmas list!

[grayjam]

Another thing you would want to look at is the fork that pushes on the release bearing. I had one time that they where slightly bend and did not give enough clearance to push and release the clutch. These things are welded with a few tagwelds and these might not be strong enough for you heavy duty clutch. I ended up welding them all around. Just my 2 cents.