Farmall Cub

There's been an oil leak on 'Popeye' where the magneto bolts onto the governor. I tried tightening the bolts, but no luck. When taking off the magneto, oil spilled out of the cavity. Is there supposed to be oil there?

Sounds like the seal behind the mag is leaking.

Donny,
Are you talking about the gasket between the mag and the governor, or is there an oil seal somewhere in there? I didn't think there would be oil in the cavity between the mag and the governor housing. Where does the oil port on the magneto lead to?

The oil port on the magneto feeds a wick system that lubricates the magneto bearings. When you remove the magneto there is an oil seal inside the governor housing that the shaft that drives the magneto extends through. This seal probably needs replacing. The instructions for it are in the manuals on Rudi's web site.

Thanks, Donny, John. I'll do the research tonight and hopefully get the parts tomorrow before the dealer closes at noon. Got my weekend's work cut out.

Pay attention to the instructions on how deep to set the seal. part number is 251379R91

The seal needs to be 23/32 or .718 from the face where the mag sits. Otherwise the seal will get chewed up by the mag. If in too deep it will likewise be chewed up by the governor gear. The replacement number for the seal is National 450313. NAPA should be able to cross it for you.

Thanks again! Y'all done did half of my research for me. John, I'm trying to find the replacement part in the parts catalog - can't find that particular number. I have a copy of the TC-37F parts catalog. What page would the part be on, or in what general section and what is the name of the part?

That seal is on the page with "crankcase and related parts." May be a different page, depending on which version of the book you have. There is an index in the back that lists all part numbers in the book and gives page references.

It's on the page showing the block, oil dipstick, rear seal retainer, etc. In my book it is Group 12, page 7, illustration 19, but as Jim said, it may be different in yours.

I'm doing the same thing now but the manual doesn't specify which side to install the seal from. Also what are you using to hammer it in?

Steve Ruddy wrote:I'm doing the same thing now but the manual doesn't specify which side to install the seal from. Also what are you using to hammer it in?

Steve,

The seal is intended to keep the oil inside the engine, so the "open" side is toward the governor. A hardwood stick with an "L" shaped notch cut for a stop will serve to position the seal and also stop it at the proper depth. Without looking it up, I think the offset stop should be at 23/32". Be really sure you have the governor properly timed BEFORE you install the seal.

Be really sure you have the governor properly timed BEFORE you install the seal.

I wish I would have waited for a reply I just came back in and the governor isn't installed yet. Hopefully I'll be OK because I have the front end disasembled as well. I ruined one seal trying to put in with a metal punch but luckily I had two and the second one I used wood cut with a hole saw and measured the depth with a printers ruler. I like Georges suggestion much better though. Let's see what else I can screw up.

George W., I'm curious about a couple things. What does it say on the top of your new avatar, and where did you get my baby picture?

John, it says "Always listen to good advice".