Billman250

I have seen two rear main seal leaks in the last 20 years. Cars were well over 180k.

I am 99% sure you do not have a RMS leak. Follow the guys advice. Clean, and monitor.

I am a little guilty here, of not reading completely. Now that I have….

Your leak is oil running down the back of the engine due to the missing cap.

YOUR CAR IS FINE.

Car Analogy

This man just saved you $5k

Buy the new cap. Clean the spilled oil.

Note, that brake clean stuff, only spray that on trans bare metal. Don't get it on paint, don't spray it under hood.

If its dirty under hood, get a can of engine cleaner. Make sure its the type for engines with plastic covers. We don't have much plastic, but you don't wanna see what happens if you use the wrong type.

Gunk engine cleaner

Buy local, cheaper. Only need one can.

Spray onto entire engine, cold. Make sure to get the areas that have oil.

Wait 10 min, hose off. Don't really have to worry about where you spray hose, though don't go crazy in alternator. Hose off the oil areas well.

Then get this stuff. Spray all over clean, dry motor, light coat. Let it sit. Next day, wipe off excess.

B serious

I wouldn't do that with brake cleaner.
But you're on the right track.

Clean it up externally with soapy water and a rag. High pressure water helps (don't spray it into any holes between engine/trans).

Clean up first. See if it still leaks.

noodels

clutch disc and brake pad are not so different though still stand to brake cleaner method it wont hurt!
the idea is flooding the internal oil in there if any ! and asses as needed being a old mechanic i would use my t shirt to wipe the little oil showing of, soapy water wtf dont have time for that

B serious

You would be washing out the grease that needs to go on the clutch splines/bearing/slides if you sprayed brake cleaner into the clutch housing