Oil leak source

I have a very minor oil leak between the inner primary case and the engine case. Not enough to make it necessary to add oil, just enough to let me know it's there. The primary is filled with ATF so I know it's not that, and I've never noticed any contamination of ATF with engine oil when draining it. Is it possible for the crank seal to leak to the outside? Also thinking it could be the gasket/bolts on the inner case, but I used thread sealer on the bolts when installed the last time.
Suggestions??

Could be one of the 3 inner primary to crankcase bolts is leaking through the outside of the gasket and not into or from the primary. I use sillycone on that gasket, they don't come off often, I've had them leak.

DogT said:

Could be one of the 3 inner primary to crankcase bolts is leaking through the outside of the gasket and not into or from the primary. I use sillycone on that gasket, they don't come off often, I've had them leak.

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+1

I just fixed a leak I found originated from the front of the primary from between it and the crank case. In my case the bolts seemed a little loose, and I retorqued with new tab washers. I think the real fix though was silicone around the gasket. Dry as can be now.

I had mine leak around the outside of the crank seal. There are two types, one with an exposed metal casing and one with a rubber covered casing, the metal one would leak even when assembled with sealant. I will now only use the rubber covered seal in this application.

Another thing that may help is a hint from hobot. Use studs and nuts instead of those 3 crank case to primary bolts. It makes it easier to put the gasket on also. But you'll have to grind down one of the nuts or the triplex chain will hit it. Then you can also use red locktite on the studs into the crank case and blue on the nuts. I'd still use the sillycone on the gasket. I don't use the tabbed washers in that case, it gets tight to put the nuts on and engage all the threads. You can get the studs at a typical auto store, they're unf/unc studs. UNC in the crank and UNF in the primary as I remember.