Clutch facing with oily contamination

Replace the clutch disc.

Release bearing slides unsmoothly on input shaft bearing retainer

Lubricate the retainer release bearing.

Wobbly clutch disc or poor facing contact

Replace the clutch disc.

Loose clutch disc rivets

Replace the clutch disc.

Weakened clutch disc torsion spring

Replace the clutch disc.

Distorted pressure plate or flywheel surface

Replace the pressure plate or flywheel.

Weakened engine mounting or loosened installing bolt or nut

Retighten or replace the mounting.