Wow...smh...I was looking for some help on my lower unit too, because I have the same friggin problem of oil dripping from the weep hole! I'm sorry that this went unanswered for two reasons...1) I feel your pain that no one offered help, and 2) I need to know! I hope you were able to figure out what was wrong.
I bought a used lower unit from a guy that said it was in perfect working condition, except for having a little water in the oil from leaking seals around the drain and fill screws. I replaced those seals, and installed the lower unit. I was off to go test it out on my boat, but by the time I got to the lake to try it out, there was oil dripping from the weep hole. I'd never seen this before in my life.
I heard from an outboard mechanic, that the shift shaft seal could cause this problem. He said the older OMC 150's were notorious for having a bad shift shaft seal. Mine is an '87 150 GT.
I'm searching the internet now to find an answer. (That's how I stumbled upon this.) I'm looking for anything regarding shift shaft seal leaking etc. and found nothing so far. Hopefully someone who works on OMC that is new to bbc since the first post will know.
Until then, I suggest you the reader do the same because this thread started in 2006, and I'm replying with the same trouble in 2013.
