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!