How does a clutch work?

[Lean L]

Any1 have a video of how the clutch works?

My guess is that the engine is connected to a flywheel, the flywheel can be connected to the tranny via friction between two plates(Is it only friction or is there a teeth mechanism?). So when you step on the clutch, a shaft pulls the clutch back making shifting easier. Does the tranny also stop completely when you pick up the clutch? Also, I hear there is a self lubrication system when the clutch is not in use?

 

[natto fire]

You kind of have it. Check out how stuff works, for a diagram. Essentially the clutch disc is sandwiched between two other discs, the flywheel and pressure plate. The input shaft of the transmission has splines that go into the clutch disc. When you push the "clutch" pedal, you are actually activating a fork that pushes a belleville(sp?) spring in the pressure plate which moves it slightly away from the clutch disc. This is a pretty bad explanation now that I actually proofread it, and there are different types, but it is a basic single dry-plate clutch overview. Like I said, a diagram is actually pretty helpful.

As far as the clutch disc, it doesn't actually move laterally, and almost all cars use a dry-plate system, so there is no lubrication involved.

 

[Zenmervolt]

Originally posted by: Captain Howdy
As far as the clutch disc, it doesn't actually move laterally, and almost all cars use a dry-plate system, so there is no lubrication involved.

There's usually a thick grease applied to the splines on the transmission input shaft, but you're sort of right since there's no mechanical system to apply oil or the equivalent.

To the OP's other question, no, the transmission does not stop completely when you disengage the clutch (unless the car is sitting still). If the car is moving, then the output shaft of the transmission will be spinning because the wheels are still spinning. The input shaft could stop (it usually takes a few seconds to spin down, which is longer than it takes a person to shift), but the output shaft will always be spinning as long as the drive wheels are turning.

Good explanation of the transmission itself.

How a single-plate dry clutch works.

ZV

 

[BlahBlahYouToo]

my question is how much abuse can a clutch take?
i've put 130k miles on a clutch before, and at that point, it felt weird (engaging didn't feel as smooth). brought it in and told the mechanic to change the clutch and when he took it off, he said it had plenty of life left on it, and put it back on. he adjusted something though because afterwards, it felt much better.

i have yet to NEED to change a clutch - think i've driven 200k miles in my lifetime in manual cars.

 

[natto fire]

That largely depends on how it is driven. It sounds like you were taught how to properly drive a manual car. I have ridden with people that slip the clutch in every gear, which wears them out pretty bad. As for the adjustment, it was probably on a cable activated one, and the cables can stretch.

ZV isn't that grease simply to prevent seizing for ease of removal for the next clutch change? I always figured that was the case, especially with the amount of heat cycling involved during normal and especially abusive use. Or does the disc need to move laterally on the input shaft? I guess it is lubrication either way, but in context...

 

[Zenmervolt]

Originally posted by: Captain Howdy
That largely depends on how it is driven. It sounds like you were taught how to properly drive a manual car. I have ridden with people that slip the clutch in every gear, which wears them out pretty bad. As for the adjustment, it was probably on a cable activated one, and the cables can stretch.

ZV isn't that grease simply to prevent seizing for ease of removal for the next clutch change? I always figured that was the case, especially with the amount of heat cycling involved during normal and especially abusive use. Or does the disc need to move laterally on the input shaft? I guess it is lubrication either way, but in context...

The clutch disc does need to move slightly along the transmission input shaft. If it couldn't move back at least a tiny bit, it would never disengage.

The movement is very slight and occurs naturally once the pressure plate is pulled back; there's no direct action to pull the clutch itself away from the flywheel, it just drifts back slightly when the pressure plate releases.

ZV