Serving as the connection between the engine and the transmission, the clutch assembly in a manual transmission withstands extreme pressures and stress on a continual basis. With a clutch's lifespan averaging 90,000 miles, problems are relatively rare. However, factors such as driving habits, fluid leaks and extreme conditions can shorten this life expectancy, resulting in signs indicating the clutch plate disc or pressure plate have gone bad.
If the clutch chatters when engaged, there is probably oil or contaminants on the clutch disc. This causes uneven friction, resulting in the clutch disc slipping and grabbing intermittently when engaged instead of seating itself smoothly as it should. Mechanical failures, such as broken springs or a cracked or broken pressure plate in the clutch assembly, can also cause chattering. Again, visual inspection is needed to be certain of the cause.
Slipping is usually a sign that the clutch disc and/or pressure plate are worn out. Normal use can wear away the lining of the clutch disc, reducing its ability to firmly grip the pressure plate and resulting in slippage. The pressure plate can also cause slippage as age and wear have reduced its ability to put adequate pressure against the clutch disc, allowing it to spin against the flywheel rather than grip it. Contaminants, such as oil and fluids from the engine, can also cause slippage if they contact the clutch assembly. Inspection is necessary to make a firm determination.
Sticking and Dragging
If when fully depressing the clutch, the gears grind during shifting, or if the clutch is difficult to disengage when pressing the clutch pedal, the clutch disc may be dragging on either the flywheel or the pressure plate. This can be due to the clutch linkage being out of adjustment, or mechanical damage within the clutch assembly is not allowing the pressure plate to move freely. As before, with other clutch problems, visual inspection is necessary to correctly diagnose the issue.
Growling, chirping or squealing noises coming from the clutch likely indicate mechanical damage. Broken pressure plate springs, worn release bearings or physical damage to the clutch disc can all result in clutch noise. Any noise coming from a clutch should be considered serious and given immediate inspection.