Q&A / Tech

Mailbag: Troubleshooting a Sticky Clutch Pedal

Q: My 1969 Roadrunner has a new diaphragm-style clutch. While shifting at high rpm, the clutch pedal sticks to the floor. When the engine speed decreases, the pedal comes back up. Can you help me out?

A: Remove the clutch pedal’s over-center/assist spring. While it was originally installed to help with heavier Borg and Beck clutches, it can hinder diaphragm clutch operation. Next, inspect the clutch linkage and adjust the pedal free-play per the manufacturer’s recommendations. You should also check your engine mounts — clutch linkage can bind if your engine is lifting under load. Finally, you may need to fabricate an adjustable stop to limit clutch pedal travel and prevent pressure plate over-extension.



This is another in a series of weekly Q&A Mailbag sessions with Summit Racing‘s tech department, in which there are hundreds more. Click here to see them all

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  1. A centerforce clutch will fix your problem. They are counterweighted to cure this issue.

    • Very true. Also, the original Borg & Beck style pressure plate that came with the car when new, had weights on the 3 arms to apply more pressure to the pressure plate at higher rpms. The reason for the over center spring was to make it easier to push the clutch pedal down. This is because the B & B style used heavier springs in it.

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