Main Seal Leak on 1961 Pan FLH

[kaptekarev]

My '61 Pan FLH is leaking a large amount of oil from the main crank seal, into the primary cover. I got to the seal and can't figure out how it's supposed to work. It's in contact with a splined portion of the crank shaft.

With the seal installed there is always a leak path between the inner diameter of the inner ring and the splined crank shaft. How is this seal supposed to function? It's not directly addressed in the service manual. Am I missing a part? How do I keep the oil in? Somehow it did work in this configuration, but now it just leaks. Please help.

[Cotten]

Kaptekarev!

It is not addressed in the Service Manuals because the Factory never intended for it to be sealed.

For a modern belt drive, you will have to use a non-hardening goober to seal between the spacer and the pulley.

Note how oil continues to flow from the bearing; It appears that your cases have filled quite full from static sumping.
Originally the slinger was an escape for oil. A seal will allow the cases to fill entirely. The hydraulic pressures from starting a motor with filled cases will quickly force oil past a rubber seal.

....Cotten

[kaptekarev]

For a modern belt drive, you will have to use a non-hardening goober to seal between the spacer and the pulley.

Thanks for the info Cotton.

By "non-hardening goober" do you mean RTV liquid gasket type stuff?

[VintageTwin]

It's too much to explain. You can buy Vol. 2 and it shows you that stuff, plus some other stuff dealing with stuff Harley or Clymers never explained. If you live outside the USA, you'll need to get it from V-Twin or Amazon. Make sure V-Twin doesn't send you Vol.1 (tan), because Vol. 2 still uses the Vol. 1 48-1958 part number. Tell them the "blue" cover Vol. 2.

https://amzn.to/3ett9Ad

The book won't help with a sumping solution. I'd look at your oil passages. Maybe pull the pump and start isolating oil passages, one by one as per the factory diagram (in the OEM '59-69 Service Manual.)

[Panacea]

It seemed simple to me, if she's sumping ,that oil has to go somewhere. Perhaps once you get a few miles on the leak may decrease to an acceptable nuisance.

[Cotten]

K asked:
"By "non-hardening goober" do you mean RTV liquid gasket type stuff?"

Sorry for the late reply: I must have hit the wrong button yesterday.

I never use RTV or any acetic acid silicone for anything around hot oil. (Not since the late '80s anyway...!)

Almost any other sealer should do: Gasgacinch, 3M #800, Yamabond4, weatherstrip adhesive, etc.

....Cotten

[rrhawg]

the spacer will butt up to the inner race of the timken bearing when the sprocket nut is tightened, and this is what seals between the sprocket and the bearing. The seal then keeps the oil from leaking around the outside of the spacer. If you use a sealer between the spacer and the sprocket I like to use 3-bond 1104 or yamabond, as mentioned by cotton. You might check the surface on the back side of the sprocket for nicks etc. Make sure you get the sprocket shaft nut tight as this holds the lower end in place.
RRHAWG