Clutches

Problem

New environmentally-friendly asbestos-free clutches are not as long lived as their previous asbestos versions. The choice appears to be chatter/judder as on some BMWs, or slippage as on our cars. The 2.5V6 coverplate clamping force is 1510 Newtons, just 27% uprating over the 2.0. Unlike asbestos clutches, the non-asbestos units can slip for many thousands of miles before failure.

Workaround

Aftermarket unit such as Centerforce Dual Friction Unit is designed for 90% uprated power but similar clutch pedal weight. It works by a dual-friction clutch-plate & centrifual weights which increase clamping force with RPM, preventing slippage problems.

ACT clutches require some clutch master cylinder rod adjustment, and do involve a heavier clutch pedal. Use of racing-puck clutches or clutches lacking take-up springs must be avoided since the shock loadings on bearings & gearbox will result in failure eventually. They are for racing use, and not road use.

Clutch specification is 225mm 8-7/8" single dry plate with 22x15/16 spline.

Replacement prices

Aftermarket US cost is around US$200-400.

Fitment labour is 4 hours, very often Mazda Main Dealers will be cheapest.

Last Upload: 31st November, 2002. V1.50a
URL: http://homepage.ntlworld.com/dorothy.bradbury/probemx/p_p5.htm