Final drive seal replacement difficulty?

[Canadian_digger]

I have a John Deere 50D that leaked out the gear oil on the one of the final drives. I was thinking of changing this seal myself, until I got a price of $1100 canadian for the seal. What I would like to know is how difficult is it to change this seal? Any special tools required. I just don’t want to make an $1100 mistake if I mess up the seal during assembly. Part number is 0397801

 

[Nige]

@willie59 did an excellent write up on replacing steel face seals without having recourse to all the factory tooling that is allegedly necessary to correctly install the two halves of the seal. It's around here somewhere - see here
https://www.heavyequipmentforums.com/threads/installing-floating-seals.36971/

 

[Tags]

Also, when it’s cold, those seals have a tendency to leak I think due to frozen mud pushing against the seal, since the mud is wedged between the sprocket and seal and it expands when it freezes. I had a machine leak one winter, completely stopped when it warmed up.

 

[Canadian_digger]

Also, when it’s cold, those seals have a tendency to leak I think due to frozen mud pushing against the seal, since the mud is wedged between the sprocket and seal and it expands when it freezes. I had a machine leak one winter, completely stopped when it warmed up.

So there might be a chance that if I thaw it out I could stop leaking?

 

[Tags]

Yep. I would try that before trying to change the seal. Doesn’t cost much…

 

[Canadian_digger]

@willie59 did an excellent write up on replacing steel face seals without having recourse to all the factory tooling that is allegedly necessary to correctly install the two halves of the seal. It's around here somewhere - see here
https://www.heavyequipmentforums.com/threads/installing-floating-seals.36971/

Thanks lots of good info in that link.

 

[Nige]

One other thing to mention is don't high pressure wash directly on to the seal under any circumstances. It could potentially drive packed dirt and mud in between the two metal rings of the face seal. As soon at the final drive starts to rotate it will likely tear up the surfaces to something resembling a ploughed field in short order. Then it's guaranteed to leak.

 

[Canadian_digger]

One other thing to mention is don't high pressure wash directly on to the seal under any circumstances. It could potentially drive packed dirt and mud in between the two metal rings of the face seal. As soon at the final drive starts to rotate it will likely tear up the surfaces to something resembling a ploughed field in short order. Then it's guaranteed to leak.

What would be the best thing to do? Warm it up in the shop and rotate the track and see if it works it’s way out on its own?

 

[Nige]

Dig it out with a pointed bar, blunt screwdriver, or similar would be my first thought. You're probably not going to get it all out but you will remove enough to take the pressure off the seal caused by the frozen material.

 

[willie59]

Have you checked the oil level in that leaking final drive? If you have an internal failure of the drive motor it will fill the planetary housing with hydraulic oil under pressure and pressurize the planetary housing, this pressure will cause leakage of the duo cone seal. Caution, make sure the oil level plug is on top before you remove it. If you don't, and there's pressure inside the planetary housing you're going to get a quick oil bath.

 

[Canadian_digger]

Have you checked the oil level in that leaking final drive? If you have an internal failure of the drive motor it will fill the planetary housing with hydraulic oil under pressure and pressurize the planetary housing, this pressure will cause leakage of the duo cone seal. Caution, make sure the oil level plug is on top before you remove it. If you don't, and there's pressure inside the planetary housing you're going to get a quick oil bath.

I haven’t checked yet. That will be the first thing I do. Thanks!

 

[John C.]

You won't get any access to the seal from the outside. It is covered up by ledges in case halves to protect the seal. The final drive has to be dis-assembled in order to get to the seal. There are lots of parts inside that can be forgotten are plain just put together wrong. A parts book would be the least amount of information that you need to have in hand and a service manual is preferable but usually leaves a lot of questions open in your mind when you are putting it back together.

 

[willie59]

You won't get any access to the seal from the outside. It is covered up by ledges in case halves to protect the seal. The final drive has to be dis-assembled in order to get to the seal. There are lots of parts inside that can be forgotten are plain just put together wrong. A parts book would be the least amount of information that you need to have in hand and a service manual is preferable but usually leaves a lot of questions open in your mind when you are putting it back together.

That's a fact. Pay close attention during disassembly, plenty of pics with your phone camera, and even then pay even closer attention with those parts. I learned the hard way doing final planetary on Komatsu CD110R-1 that there's notches in the planet gear carrier that has to be indexed a certain way. Some planet gear housings are easy, some are very particular, one mistake can cost big bucks. And y'all may call me crazy, but when I was going to bust into a planet gear housing to do a seal replacement I would drain the nasty smelly gear oil then add a good dose of diesel fuel in the housing, slowly rotate the motor a couple of turns in both directions, drain the fuel, then repeat the process just to kinda rinse some of that nasty a$$ gear oil out of the parts before I bust it down.

 

[Nige]

And y'all may call me crazy, but when I was going to bust into a planet gear housing to do a seal replacement I would drain the nasty smelly gear oil then add a good dose of diesel fuel in the housing, slowly rotate the motor a couple of turns in both directions, drain the fuel, then repeat the process just to kinda rinse some of that nasty a$$ gear oil out of the parts before I bust it down.

We used to do exactly the same to excavator finals that were contaminated with dirt to flush them. Works a treat IMO.

 

[willie59]

We used to do exactly the same to excavator finals that were contaminated with dirt to flush them. Works a treat IMO.

LoL, I'm glad to see I'm not the only one that thinks "outside the box" Nige, although I'm not surprised to be honest, I'm quite certain you have a number of similar tricks up your sleeve from years of experience. As a seasoned mechanic and jack a$$ of all trades I have a high tolerance for offensive odors, comes with the trade. But one odor I will never grow immune to is nasty a$$ gear oil.

 

[Nige]

Also why I prefer TO-4 oil over EP gear oil for final drives any day if the week…….

 

[willie59]

TO-4 is some good versatile $hit.

 

[mg2361]

Check your PM.