Clutch Contamination

Fluid contamination is a frequent cause of clutch malfunctions. Oil, grease, water, or other fluids on the clutch contact surfaces will cause faulty operation. The usual result is chatter, slip and grab.
During inspection, note if any components are contaminated. Look for evidence of oil, grease, clutch hydraulic fluid, or water/road splash on clutch components.
Oil contamination indicates a leak at either the rear main seal or transmission input shaft. Oil leaks produce a residue of oil on the housing interior and on the clutch cover and flywheel. Heat buildup caused by slippage between the clutch cover, disc, and flywheel can sometimes bake the oil residue onto the components. The glaze-like residue ranges in color from amber to black.
Road splash contamination means dirt/water is entering the clutch housing. This may be due to loose bolts, housing cracks, or through the slave cylinder opening. Driving through deep water puddles can force water/road splash into the housing through such openings.
Clutch fluid leaks are from loose or damaged clutch linkage fluid lines or connections. However, most clutch fluid leaks will usually be noted and corrected before severe contamination occurs.
Grease contamination is usually a product of excessive lubrication during clutch service. Apply only a small amount of grease to the input shaft splines, bearing retainer, pilot bearing, release fork and pivot stud. Excess grease can be thrown off during operation and contaminate the disc.