F115 main upper crank seal leaking

[rodbolt17]

no PCV valve.
but from your other thread there is likly ring damage and excessive blowby.
I would do a leakdown test before worrying about an oil leak.

[Coreylaker]

So the blow-by would cause excessive crankcase pressure? What would the likely cause of ring damage?

[Coreylaker]

Keeping crank shaft stationary?

I'm attempting to remove the cam drive nut from an '05 F115. Can anyone tell me how to keep the crank shaft in place so I can remove the nut?
Thanks

[TownsendsFJR1300]

I'm attempting to remove the cam drive nut from an '05 F115. Can anyone tell me how to keep the crank shaft in place so I can remove the nut?
Thanks

An air gun with an air compressor should zip it off.

Re the possible blow by past the piston rings. Their either worn out (due to a large end gap now from wear and tear, low oil, etc). The compression that should be above the piston is blown past the rings/cylinder and into the crankcase causing excessive positive pressure below the pistons.

That excess pressure is likely blowing out the seal.

[Coreylaker]

Thanks Townsends.
Makes sense, but certainly not good news. If I can get the cam nut off to expose the upper seal I plan to attempt Rodbolt's advice on replacing it.
Are there any solutions you can think of short of rebuilding the motor? I picked up last fall to just to power a pontoon on a tiny lake in Michigan so it won't be getting much use.

[TownsendsFJR1300]

Thanks Townsends.
Makes sense, but certainly not good news. If I can get the cam nut off to expose the upper seal I plan to attempt Rodbolt's advice on replacing it.
Are there any solutions you can think of short of rebuilding the motor? I picked up last fall to just to power a pontoon on a tiny lake in Michigan so it won't be getting much use.

I PM'ed you...