These days, almost all clutches ‘self-adjusting’
DEAR TOM AND RAY: What’s 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 isn’t adjustable.” Why would they make clutches nonadjustable? — Trudy
TOM: They don’tmake clutches “nonadjustable,” Trudy. But they do make most of them “self-adjusting” these days, which means they can’t be adjusted by your mechanic.
RAY: Since you’ve 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.
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 gets higher and higher. Eventually, all the free play disappears, and then you’re riding the clutch all the time
Click & Clack Talk Cars without knowing it.
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 didn’t remember.
TOM: So 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 there’s no more adjustment room left, then it’s time for a new clutch.
TOM: If the engagement point for your clutch has gotten too high, that’s probably the case.
RAY: But if it’s too low, 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 if it improves, your next step would be to find and fix the leak.