Clutch question

[jamathe]

Hey everyone, since I know nothing about cars I wanted to put this question out there for you all.  I've never really known why clutches go bad and now that I have a stick shift I thought I better find out.  So if I am at a stoplight or in rush hour traffic, is it worse to hold in the clutch or is the # of times you push in the clutch that makes it wear down?

[Eric18T]

iirc the material starts to get worn from being in the engagement process and then once it gets thin it is done.  If you are putting more force on the clutch it will wear sooner.  I beleive heat on clutch surface also plays a role in the wear.. If i am wrong please correct me.

[kraut-sled]

If by Holding the clutch in, you mean having it fully engaged and your foot on the floor, then that is fine.  You just do not want to use the cluch to "hold" the car still as opposed to using your brakes.

Holding the car with the clutch is not a good idea.  It creates heat, which can cause premature failure.  It also puts prolonged stress on the throw-out (release) bearing.

Most of the clutch failures I see are because the Throw-out bearing fails, or the fingers on the pressure plate brake.  But then again most of our customers are a little rough on their cars, and these week areas fail sooner.

HTH

[34k]

From my limited knowledge: If you have the clutch depressed at any time, you are working your throw-out bearing causing wear. Also, with our hydrolic clutches, I believe resting your foot also keeps the clutch from readjusting itself as your pressure plate wears down over time.

Most of the wear and tear on a clutch happens under transition to load. Over time, your friction plate can wear down just like brake pads from matching the rotational speed of the flywheel with the rotational speed of the clutch. This can be exacerbated by slipping or riding your clutch a lot where you are in motion under throttle but not fully off of your clutch pedal. An example of having to do this in every day life would be starting on a hill where you have to come off the clutch slowly to prevent a stall. Another example is launching down the "1320" or quarter mile but I think that deserves a different thread.  :wink:

For my part, I keep my foot off of the clutch whenever possible, including stoplights.
(edited for some creative spelink)

[gragravar]

this site has a really good diagram on how a clutch works:

http://auto.howstuffworks.com/clutch3.htm

in the mean time, you should be OK with the clutch all the way to the floor, or all the way engaged (foot off it).  you get wear in the transition between those points.

[SweetVW]

This is great info.  I knew that riding a clutch was bad, but without takig one apart or seeing the parts loose, I too was not sure exactly the right info.

[jamathe]

Awesome, thanks for all the info.  I went and looked at the info on www.howstuffworks.com and that really helped me understand.