The rear main seal is a for your crankshaft. It allows the flywheel to bolt up to the crank, without engine oil leaking all over the place. So if you see oil dripping from the rear of the engine, that is probably your rear mail seal leaking. Very common.
Well, to replace the rear main seal means you have to remove h-pipe, driveshaft, transmission, bell housing, and the clutch assembly.
My guess is around 300-500 dollars. Probably more like 400. Call around for some quotes. Make sure you tell them what kind of transmission you have.
If your clutch has a decent amount of mileage on it, I would replace it. Definately worth it. How slow is the leak? Most people just make a habit of putting oil in their car every 2 weeks or so.
Scott
It is very slow. A few drips a week. I just wanted to make sure it was just oil and not something more important. I will be selling the car in the spring, so I was hoping that this was nothing major.
Car is mint, but has 130K on it. Stock clutch, but I drive it very modestly so there is still a considerable amount of life left in it considering the mileage. (No slippage, and the gears grab just fine even under heavy load).
I will be selling her to a friend, I know that he is gonna beat it like a red headed step child so the clutch won't last long. I will pass on the info. to have it all fixed at the same time to save on labor costs.