Slipping is one of the most common clutch problems. Slipping can occur right after installation or after years of service. A clutch slipping condition on a manual transmission equipped vehicle will manifest itself as excessive RPMs in the engine, but lack of acceleration.
There are 3 primary causes of slipping:
- Oil leaks, over lubricated input shaft causing contaminated friction material
- Misadjusted, binding, or worn release system, or blocked master cylinder compensation port.
- Improperly machined flywheel.
Listed below are diagnoses of some different reasons for slipping:
- Contaminated friction material can contribute to a slipping condition caused by the loss of the material's coefficient of friction.
- If a vehicle has a hydraulic or manual cable release system, it is important to inspect for a binding condition. A release cable may be worn, stretched, or kinked.
- Another reason for slipping is improper step and cup dimensions after a flywheel has been machined. This would cause a "thick disc condition." A thick disc condition is a flywheel step that is too tall, or a flywheel cup that is too shallow. Due to the characteristics of the diaphragm spring the clamp load will be diminished, leading to a slipping condition.