Farmall Cub

Yet again we're faced with oil winding up inside the distributor cap ('63 cub, distributor not magneto). The oil seal was replaced and we thought we had it… but then it started leaking again with use. This time around I'm trying to figure out what is causing the leak - and I noticed that I can grab the rotor (or shaft if I remove the rotor) and move it up and down (and side to side) quite a bit (1/16" of play or so is a quick guestimate). Is this normal, or should I be looking to replace the shaft (or entire distributor)? My theory is something is causing either excess oil pressure or something is wearing that seal and I'd rather fix it than keep replacing seals:)

Any other ideas of what is causing this recurring leak are welcome too!

I'm not an expert like the other guys here, but are you lubricating the distributor with oil or grease? The manual calls for grease from a gun. If you're putting oil in there it could be your problem.

Is it the govenor seal you've replaced? A worn governor seal will cause excessive oil inside the distributor.

Governor seal replaced twice now with a new one by someone with a lot of cub experience.

And we're not talking a little oil like might come from lubrication of the distributor itself - it can be a PUDDLE, and sometimes puddles down near the front axle as well (after having streamed or dripped down from the cap).

Right now I think it is one of the following:
1) Worn bushing (or shaft) allowing the governor seal to be opened up a bit over time… then leaking like a sieve
2) internal seal within distributor leaking (looks like an O-ring to me in the parts diagram, but not having had the distributor apart I'm not sure).

If I can find a rebuilt distributor I may just spend the $ and swap them out (should have before now… may snow tomorrow and this is used for plowing). Otherwise I'll try and replace all the bits I can think of.

Unless you are oiling the distributor rather than greasing as you should it has to be coming past the "magneto" drive seal which is actually on the governor. Since you have replaced it twice, i would suspect there is a scratch on the side of that shaft that is wearing the seal, unless the governor itself has a lot of play in it. Only one guess how I would know that. Ended up removing the governor and using a burnishing wheel in a Dremel to smooth the shaft.

I did one that leaked and ended up I had driven it in to far. The depth of the seal should be 23/32 and I thought that if I put it in just a little further I would hit a smoother surface on the governor drive. That what I get for thinking.

If this is the Cecil I think it is this is your nemesis tractor in the north country - it's leaking again… just in time for winter!

I'll just never learn to keep my mouth shut.

Cecil wrote:...That what I get for thinking.

A headache?

Cecil did a great job on the machine and has been a big help overall. But some cubs are just "special"… and this is one of them!

I'm heading up to tackle this a bit tomorrow. I'll likely start with a compression test, as I really want to be sure that their isn't something else going on…. and a broken ring or other compression problem is about the only thing I can think of that might cause extra pressure on that side of things (well, that and / or a blocked breather cap.)

If I still had my trailer I'd bring it down to my house (with all my tools and somewhat heated garage). Working outside on vehicles in the cold reminds me too much of my teens and twenties!

Only 2 things will cause the leak.Seal or bad grove in governor. I think it is a seal problem

Call me if you need help.

The GOOD news is that the compression was 100, 100, 95, 95.

I took the distributor off. I think it is the seal inside (may be an O-ring… not sure yet) that I see on the parts diagram, I'd assume (ha!) the gear at the end of the shaft needs lubrication… and it gets it by the looks of it (rather oily).

Here's hoping the roll pin comes out easy.

If I get in to a jam I'll ring you Cecil - thanks.

Boss Hog wrote:Only 2 things will cause the leak.Seal or bad grove in governor. I think it is a seal problem

Dat wud B a big yup. Oil is coming past the Magneto/distributor drive seal. Oil has to pass that seal before it gets to the distributor.