First off, yes I did do a search and I read through the FSM with out gaining answering my question. My truck is leaking oil pretty heavily. :'( It appears to be coming from the little semi-circular hole on the face where the engine and transmission mate together (right above the front sway bar). The local hot rod guy climbed under and took a quick look. He said the it was my rear main seal. My question is how do you properly diagnose this? And what’s a good guess how much is this going to cost me to have fixed? Thanks.