1990 Nissan D21 Clutch Assembly Adjust Cost

Clutch assemblies are used for manual transmissions to be shifted through a set of gears without damaging the transmission or gear sets. It is mounted to the engine's flywheel, and the transmission's input shaft is locked into the clutch disc. This provides the clutch the opportunity to lock the engine to the transmission, and transfer power from the engine to the transmission.

When the clutch is engaged - clutch pedal not pressed - a large spring pressure the pressure plate into the clutch disc, which is then pressed into the flywheel. This causes the engine flywheel to turn the transmission input shaft at engine speed. When the clutch pedal is pressed, the clutch disc, flywheel, and pressure plate are no longer pressed together. This allows the clutch pressure plate and flywheel to rotate independent of the the clutch disk. Since the clutch disc is connected to the transmission input shaft, the transmission input shaft will slow down quickly to allow shifting.

If the clutch is unadjusted, one of two things will happen. The clutch could fail to engage and slip while the clutch pedal is not pressed, or the clutch could fail to fully disengage when the clutch pedal is pressed to the floor. In both situations, clutch material will likely be burned off, and the driver and passengers will smell the clutch friction material burning off at some point. Also, after extended use of an unadjusted clutch, the clutch may fail entirely, and the transmission can no longer be locked to the engine.

The clutch is expensive to replace but cheap to adjust. For this reason alone, the vehicle should be brought in for inspection as soon as issues arise. Also, since normal operation of the clutch is typically necessary to operate a vehicle, the vehicle will likely be useless until repaired or adjusted.