Technical Articles

Clutch

REPLACING A CLUTCH sure plate (which are normally a little thinner than standard).
My story is also about a faulty clutch. When I restored my beloved "Gromet", I fitted an almost new clutch kit. It had been removed from a 'free bee' that I had obtained from a lady who had made a bad mistake in purchasing a very rusty Morris Minor and trying to have it repaired to roadworthy condition. You know the sort of lady, "I must have one of those cute Morry's with the curvy sexy shape....". And then a month later it is for sale because the car is too slow, or the pedals are too close together, or (and this is true) "the seat is not as comfortable as my BMW"!! Anyhow, this lady who gave me the freebie had receipts showing the brakes had been reconditioned and a new clutch fitted. And when I removed the clutch it looked very shiny and new.
But Grommet, fitted with the new clutch, was not a happy lad! The clutch was VERY heavy and a bit sharp. It slowly got worse until it was making rattling noises every time I pressed down on the pedal. Engaging the clutch became an art - it was so violently sharp, and it started to make loud squawking noises, like a pig in pain!
So out came the gearbox and the clutch. The carbon thrust release bearing was broken in three pieces. The friction and pressure plates looked fine. However, on close examination it was evident that one of the friction plate springs had been rubbing on the inside cover of the pressure plate assembly. Very strange!
I took the lot down to my local clutch expert with a spare clutch pressure and driven plate. The story I got from the experts was interesting. They suspected that the fault was caused by a wrong or faulty pressure plate (springs to heavy) and a friction plate that had the springs protruding too high. The excessively heavy springs of the pressure plate caused the carbon thrust bearing to disintegrate.
There experience has been that the friction linings on new driven plates vary in thickness, not because they are designed to be used in new or old pressure plates, but apparently due to lack of quality control. They recommended that whenever a new, old, or reconditioned clutch is fitted, it should be checked. So... be warned.
My spare friction and pressure plate were adjusted and now the clutch works perfectly.