If the clutch is worn out you may want to buy the whole kit. Anyhow, there is one (that I know if) 'oil proof' clutch... otherwise oil impregnation will decrease its lifespan/effectiveness. However, if you have a bunch of oil down there you may just want to take the extra few minutes and replace the rear main seal anyway. If youre able to do the clutch then you can easily do the rear main. Good luck.