rear axle lubrication

Brians 8N

New User
I had a slight oil leak and no brakes at all on the left side so I decided to take the axle apart and replace the seal. According to the shop manual I am supposed to pack the outer bearing with grease. I do not have a problem with doing that but I am a little confused on a couple of things that I hope someone can help me out with.
The outer bearing did not have any grease residue on it. It looks like someone was in here before as a lot of the components inside the brake drum looked new compared to the right side (rusty).
When I look at the dipstick (cover on right hand side) for the rear end oil level and kind of eyeball where that level would be in relation to the axle housing, the full mark is well below the axle housing.
How does the inner bearing get its lubrication? I am going to assume splash but are the components inside the rear end moving fast enough to splash oil on that bearing?
Why would I have to pack the outer bearing with grease if oil would work its way down the axle shaft and (in my case) leak past the seal?
There did not seem to be a lot of oil on the axle when I removed it but it has been a while since this tractor has moved under its own power but the brakes were coated in oil and the seal area was damp.
Am I missing something here?
 
Brian, welcome to the forum - Glad to have you!!

In addition to TG2's response, if you have a 1950-1952 8N, it will have both inner and outer axle seals where early models have only an outer seal.

Late models require the wheel bearings be packed due to being isolated from differential lube oil.
 
Bill, below is correct.

Early 8Ns had only outer seals and the axle bearing was lubricated with differential oil.

This design was troublesome and the later model 8Ns have an inner oil seal and an outer grease seal. The axle bearing must be packed with bearing grease. The inner seal is intended to keep the oil inside, away from the bearing. If it leaks, the oil will eventually wash the grease from the bearing and contaminate brakes. The outer seal is intended only to keep the bearing grease from the brakes.

That said, not everyone knows this and it is not uncommon to disassemble a late model 8N axle to find that an earlier repairer reassembled the axle without packing the bearing.

Dean
 
(quoted from post at 22:35:41 06/20/18) I had a slight oil leak and no brakes at all on the left side so I decided to take the axle apart and replace the seal. According to the shop manual I am supposed to pack the outer bearing with grease. I do not have a problem with doing that but I am a little confused on a couple of things that I hope someone can help me out with.
The outer bearing did not have any grease residue on it. It looks like someone was in here before as a lot of the components inside the brake drum looked new compared to the right side (rusty).
When I look at the dipstick (cover on right hand side) for the rear end oil level and kind of eyeball where that level would be in relation to the axle housing, the full mark is well below the axle housing.
How does the inner bearing get its lubrication? I am going to assume splash but are the components inside the rear end moving fast enough to splash oil on that bearing?
Why would I have to pack the outer bearing with grease if oil would work its way down the axle shaft and (in my case) leak past the seal?
There did not seem to be a lot of oil on the axle when I removed it but it has been a while since this tractor has moved under its own power but the brakes were coated in oil and the seal area was damp.
Am I missing something here?
ote: outer seal is seal to hub, not seal to axle.
 
Thanks for your input guys, it is really nice to be able to go to this forum and get advice.
My tractor is an early 8N (serial number indicates 1947) and it only has the one seal. I wondered why the parts manual showed other seals but there is no place to put them.
Now to my other question. Am I correct about the oil level in the differential? There is only the one dipstick and if I eyeball the full level related to the dipstick it is well below the axle housing. How does the oil get to the outer bearing? I know it does otherwise I wouldn't be leaking oil.
 
(quoted from post at 08:53:53 06/21/18) Thanks for your input guys, it is really nice to be able to go to this forum and get advice.
My tractor is an early 8N (serial number indicates 1947) and it only has the one seal. I wondered why the parts manual showed other seals but there is no place to put them.
Now to my other question. Am I correct about the oil level in the differential? There is only the one dipstick and if I eyeball the full level related to the dipstick it is well below the axle housing. How does the oil get to the outer bearing? I know it does otherwise I wouldn't be leaking oil.
rive tractor around while working with a half full glass of water and see how much you have left at end of day. Same way oil moves about.
 

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