My oil leaks were getting larger. Really only one place it could all be coming from (after looking at everything else): rear oil seal. So I spent a couple of hours disconnecting things, then had my friend Max help me take the engine off and replace the seal. It took me a few hours to reconnect everything.
The rear oil seal sounds like a big deal, but it's more of a nuisance than anything. It's a weekend project.
Cost of seal: $8.00 Time to disconnect stuff: 2 hours Time to replace seal: 2 hours (but most of that was trying to get the right shim spacing) Time to reconnect everything: 3 hours
You can see in the photos that I left the accessory plate attached to the engine mount, and instead just removed the engine from the accessory plate. There's much less to disconnect and reconnect that way.
Why was it leaking? I think for two reasons: 1. I fly a lot of aerobatics, which I'm guessing puts added stress on the seal 2. My crankshaft end play was likley out of the max .006 travel range, which probably helped accelerate the wearing of the seal, and may have contributed to the crank "pumping" oil out the seal because of the piston motion of the crank.
