Mercedes® Clutch Disc,1968-1983 (123)

If the clutch fails to release (pedal pressed to the floor, shift lever does not move freely in or out of reverse);you notice a grabbing or chattering when clutch is engaged, or a squeal or rumble with the clutch fully engaged (pedal released); the clutch disc or pressure plate may be warped or cracked. The release bearing needs to be checked also to make sure it is not binding..