Dear Tom and Ray:
Whats the deal with nonadjustable clutches? I have driven manual transmissions my whole driving life. I own a 2007 Toyota Matrix and when I started stalling it more often due to the clutch, I asked the dealer if he would adjust the clutch for me. He said, No, the clutch isnt adjustable. Of course, Id never heard of such a thing, and wondered if he was just blowing me off as a woman driver who didnt know what she was talking about. Why would they make clutches nonadjustable? Trudy
Tom: They dont make clutches nonadjustable, Trudy. But they do make most of them self-adjusting these days, which means they cant be adjusted by your mechanic.
Ray: Since youve driven stick shifts all your life, you know that in the old days, clutches routinely had to be adjusted.
Tom: Normally, you always want there to be an inch or so of free play in the pedal. That means for the first inch or so that you depress it, nothing happens. The pedal just flops there. Theres no resistance.
Ray: That tells you that the clutch is properly adjusted, and is not riding itself (being partially disengaged at all times while you drive around). Because a ridden clutch is a not-long-for-this-world clutch.
Tom: Normally, as a clutch goes out of adjustment, the engagement point (the point at which the car starts to move as you lift your foot off of the clutch pedal) gets higher and higher. Eventually, all the free play disappears, and then youre riding the clutch all the time without knowing it. Its as if your foot is partially on the clutch pedal, even though its not.
Ray: Eventually, people got sick of having to (1) remember to get the clutch adjusted all the time and (2) replace their burned-out clutches when they didnt remember.
Tom: So, to satisfy their increasingly annoyed customers and protect their reputations for reliability, manufacturers started using hydraulic, or cable-based, self-adjusting clutches which do what? They adjust the amount of free play, all the time, by themselves.
Ray: At some point, when theres no more adjustment room left, then its time for a new clutch. You may be at that point, Trudy.
Tom: If the engagement point for your clutch has gotten too high, thats probably the case.
Ray: But if its too low, there are two possibilities. One is that some air may have gotten into your hydraulic system through a small leak in the slave or master cylinder. You can have the system bled to remove any air thats in there.
Tom: If it improves after being bled, your next step would be to find and fix the leak.
Ray: The other possibility is that you bought some extra-thick or all-weather floor mats that are making it impossible for the pedal to reach all the way to the floor.
Tom: My brother picked up another inch and a half of downward clutch travel by removing the full-pile shag carpet he had in his car.