Clutch Assembly: Inspection

Check clutch facing for cracks and wear by measuring depth of each rivet head. Minimum depth at any rivet is .020" (.50 mm). See Fig 1 . Replace clutch disc if worn or damaged. Measure clutch disc runout. If runout is greater than .031" (0.8 mm), replace clutch disc.

Fig 1: Measuring Clutch Disc Rivet Depth
Courtesy of GENERAL MOTORS CORP.
Check pressure plate for warpage, heat marks (blue coloration) and cracks. Check pressure plate diaphragm spring fingers for wear and uneven height. If pressure plate assembly is excessively worn or damaged, replace pressure plate. Check release and pilot bearing rotation. If roughness is felt, replace bearing. Inspect flywheel for heat marks and runout. If flywheel runout is greater than .004" (0.1 mm), replace flywheel.
Clean oil, grease and metal deposits from flywheel and pressure plate. DO NOT use air hose to clean clutch parts. Slight surface scoring can be removed with sandpaper. Replace or repair as necessary.