Does this look more like case leak than rear main seal?
 

My 79 930 engine runs higher than normal oil pressure and I used 5w-40 fullsyn last summer and got some leaks from trans/block area. Cyl 3 base gasket and this area in pics.

What is that grey stuff? About 25000 miles from a big overhaul. Base gasket was my own work and now I will use hylomar blue plus possibly the 964t oil ring if I can find the grooves on the spigots of the cylinders. I will change all base gaskets and ct2 head gaskets. Steel head studs seemed fine.

http://forums.pelicanparts.com/uploa...1616739923.jpg
http://forums.pelicanparts.com/uploa...1616739923.jpg
http://forums.pelicanparts.com/uploa...1616739923.jpg

Looks like at some point someone gooped on sealant in an attempt to stop a seal leak.

Is that sealant (soft) or epoxy (hard) around the seal? It looks like marine epoxy to me, same stuff we used to use inside intake ports on racing heads.

Its hard. If I deside to replace the seal if I can find kaco or elring seal does that require dremelin or some special removal? I just ordered loctate 290 for the seam, but what should I put over the seam after 290? Someone put JB but that sound a bit hardcore?

my 0.02c worth.. I don't think that part of the case is prone to leaking unless not sealed correctly when assembled.. but looks like the oil has come from top down.. ie, breather hose and breather gasket... It surprises me how much can come out of there..

But seeing as you have the engine out and on a stand, I'd be contemplating rebuilding it anyway.

FWIW, I think the epoxy was put there to keep the seal from walking out and not to prevent oil from leaking out. Just a guess of course.

It seems that way to me also. Its rough and not evenly put. So I guess I need to dremel it of and try to be carefull with the block.

If the material is brittle, you might find that tapping on it with something like hard plastic or a piece of wood might shatter it causing breakaway negating the need to grind on it.

Just to confirm: those stock pilot bearing bolt holes are just filled with leaked oil, not something that should be blocked right? I use 77 930 clutch setup so my pilot bearing is on the flywheel and those crank holes are unused. I just ordered new elring RMS but havent had time to thorougly clean that area yet. Cylinders and heads take a lot of time to clean.

Aircraft paint stripper with methylene chloride works great to remove burned on carbon on pistons, heads, valves..... Paste it on, wait 10 minutes and the carbon wipes right off. Do this outside with double nitrile gloves and respirator....
David

Reclino. Thanks but those are forbidden in EU.