So I have a 2001 z28 and I've noticed an oil leak right around where the transmission and the oil pan meet. It's not much but it's getting annoying. I think it's the rear main seal but I heard that it could also be the oil pan gasket. Is there any way to tell the defference? Thanks for the help.

 

Unfortunately, the only way to tell if it's the rear main seal is to pull the transmission and inspect. Is it dripping out of the little rectangular hole at the bottom of the transmission?

 

Make it easy on yourself and just order a replacement back-plate with rear main seal already installed from the dealer, it's less than $50. Pull out the transmission, remove the back plate and install the new one with some grey silicone at the corners.