Farmall Cub

If the transmission is filled with the proper amount of gear lube, will any come out past the transmission input seal under normal circumstances, even if the seal is no good?

When we loaded the '53 on my trailer to bring it home, we thought we struck oil by the amount that came out the torque tube. Definitely gear lube, by the smell. After I had it split, I shined a light down in there and you can see where oil has been running out the seal, and the puddle in the torque tube.

This is mostly a thought exercise because the hood is off, and replacing the transmission input shaft seal is one of those "may as wells."

Before I replaced the original transmission seal, gear lub would drain/leak out the front of the torque tube when I got the Cub's nose sharply down. I use the Cub many years with the front seal leaking because it didn't appear that I was loosing enough gear lub to bother with.

Matt,

I would suspect that the seal is there to do just that, retain the fluid in the tranny. Just be careful running the new seal down the input shaft. If you do not clean the shaft well, you'll destroy the seal lip by the time it makes it to the proper position. Gary

LOL, I agree with you Gary, just wondering how important it really is.

The level check plug for the transmission is way low on the casting, and the input shaft is nearly at the top. Unless you're really going down a steep hill, I can't see how that much oil can escape.

As long as there is oil enough for at least one of the lower gears to run in it, oil will be slung into the oil distribution trough. From there, it is distributed to an oil hole that leads between the front bearing and the seal. If the seal is bad, oil will go past it.

If you do put a seal in it I have a slick way of putting a seal in the old retainer , as they fit like the rear seals do a bit loose
Boss

I'm interested to see what you do with it, Boss. I am going to have to do Lewis' tranny soon, and I was hoping to use the NAPA seal...

I am also very interested, since I am planning to finally do mine this January when we have our "mini-fest" here! Please, fill us in, Boss!!

Jim Becker wrote:As long as there is oil enough for at least one of the lower gears to run in it, oil will be slung into the oil distribution trough. From there, it is distributed to an oil hole that leads between the front bearing and the seal. If the seal is bad, oil will go past it.

I agree, oil is running into this area all the time the tractor is moving to keep that front bearing lubed.
There's a small cut out on the seal retainer that allows excess to run back in the trans and away from the seal but even with that helping it'll still leak through. Be sure the retainer insets into the trans the way it comes out.

I did mention that this was a "thought exercise" right?

I got bored last night, so I did this:



Now we play the waiting game... Hopefully the new seal will be here in a couple of days.

BTW, the jack is not the only thing holding up the torque tube. My "pogo stick" splitting stand is bolted on there too, set just a fraction above the floor so if it slipped of the jack, it wouldn't go anywhere.

It wouldn't be much more work to do the bearings now if they need it. I wish I did when I split my loboy down. Been kicking myself ever since.

Take a wire brush to the shaft, one on a grinder works best to get the rust off , coat the shaft with oil. When you go to put the seal in most likely it is goping to be too small and will be a loose fit. lightly center punch a few places in the retainer, glue the seal in being carefull not to get any on the rubber. when you replace the 3 bolts use a flat washer under each one that will hold the seal in.
Boss

How do you get the old seal out of the retainer? It appears that the retainer completely encases the seal on both sides, and the seal needs to be cut out, destroying the retainer in the process.

drive it out from the back side

Really? I don't see a seam on the front side of the seal retainer. I looked real close, under good light. It appears to be one solid piece of metal.