Neon main seal

I had my 97 Neon head gasket and rear mail seal replaced last month due to leaks. My mechanic showed me the rear seal which had been rubbing against the fly wheel and had rubber worn off the back side. My main seal has begun leaking again. Does anyone have any ideas what could be causing this?? The engine has only 45K miles and I have owned it since new and has never been crashed.

thanks much

How do you know it's the rear main seal? It could be your camshaft position sensor leaking.