Westerbeke 42b oil leak

[Rocinante33]

Hi all

I have a small leak from the back of my 2003 westerbeke 42b engine. This started right after the pressure sender failed and was replaced (twice). I think now that was just a coincidence, though I originally tried to trace the leak to the switch.

Wrapped the new switch and the new oil filter with paper towel and no leak apparent there. There is a sort of spray pattern of oil on the bilge floor right underneath where the tranny meets the engine block and it leaks about a capful of oil per every couple hours running. Not too bad, but it it will probably get worse and oil absorbers seem like a temporary fix.

I fear that it is the rear main seal.

It looks like the tranny will have to be detached and in order to do that, the prop shaft will have to be decoupled and slid back a few inches. Can this be done on the water? Or do I need a haulout? Does anybody have first hand experience?

Do I have to use the westerbeke OEM? There are a lot of post forums about westerbeke and their parts piracy policy. My personal experience is that I have ordered four separate OEM parts from westerbeke directly or through dealers and had two of those four fail almost immediately (but after 30 day warranty). Replaced both with NAPA parts because I was a long way away and they have worked fine. If anybody knows the parts cross reference (and whether the rear main seal was one of those parts that WB ‘tweaked’ I would be grateful.

Lastly, I don’t think I can do this myself. How many hours (roughly) will this require? (I know, I know….but engine is clean, no rust and has been regularly serviced)

Thanks in advance for any thoughts

Cheers!