The MGB clutch is a Borg & Beck single dry plate diaphragm spring type, 8 inch in diameter on all four-cylinder models, actuated hydraulically via the clutch master cylinder and slave cylinder. The clutch plate, cover, and release bearing are all serviceable items and replacement is straightforward with the gearbox removed. The same basic clutch specification was used throughout production from 1962 to 1980 on four-cylinder cars, though the release arm and its gaiter differ between three-synchromesh and four-synchromesh cars, and between chrome bumper and rubber bumper cars. The release arm (also known as the clutch fork) differs between gearbox types: three-synchromesh and four-synchromesh cars use different release arm specifications.
The release bearing clips to the release arm and both the release bearing clip and the release arm fitting kit are available. The release arm gaiter also changed between production eras, chrome bumper cars use the oval section gaiter, while rubber bumper cars use the rectangular section type. Both are available.
Clutch Kits
The clutch kit is available with either a carbon-type or roller bearing release bearing. The roller bearing type is the recommended alternative, it offers improved reliability and avoids the premature wear that can affect carbon-type release bearings, and is supplied complete with attachment clips. Clutch alignment tools are available for both engine types: one for 18G and 18GA engines (1962 to 1964) using the smaller first motion shaft spigot, and one for 18GB, GD, GG, and 18V engines from 1965 onwards. The correct tool must be used to match the gearbox fitted to the car, not simply the engine, as components from earlier cars may have been changed.
The MGOC Spares range includes the clutch roller bearing kit, release bearing clip, release arm fitting kit, release arm pivot bush, release arm pivot bolt, plain washer, locking nut, clutch release arm gaiter for chrome bumper cars, clutch release arm gaiter for rubber bumper cars, and clutch alignment tools for both engine specifications. All associated fixing hardware is available.