Leaking Gear Oil By Front Differential Bevel Pinion Shaft / Damaged Collar

[softwrangler]

Hi All,

My Kubota BX24D tractor is leaking gear oil by the front differential bevel pinion shaft (see yellow highlight on attached bevel pinion shaft picture). After I noticed the gear oil leaking, I drained the gear oil from the gear box. Then I removed the gear shaft and oil seal. Behind that I found a damaged collar (see damaged collar picture). Since the seal was only $13, I replaced it in hopes that the damaged collar wouldn't affect the sealing of the gear oil. Unfortunately, the gear oil still leaks. So I bought the Kubota manual and have attempted to remove the bevel pinion shaft as per the instructions. However, after removing the internal snap ring I couldn't pull out the bevel pinion shaft and associated collars/lock nuts. It looks to me like #3 in the top photo should slide right out (see instructions of removing the bevel pinion shaft picture and the yellow highlighted step that doesn't match what I am seeing). Before I go any further, I thought I better seek advice from those more knowledgeable than myself. I haven't had to deal with this type of issue before. What are your thoughts? Should I continue to replace the damaged collar? If so, does anyone know how to get the bevel pinion shaft and related collars out of the gear box?

Thanks in advance --- Pat

 

[MOOTS]

By the looks of your picture, the snap ring is still there. 11 and 1 o’clock are the nubs to remove.

Also, I had a F mower leaking at work. Puts some gasket maker on the seal and that worked.

 

[softwrangler]

By the looks of your picture, the snap ring is still there. 11 and 1 o’clock are the nubs to remove.

Also, I had a F mower leaking at work. Puts some gasket maker on the seal and that worked.

Hi Matt,
Thanks for the quick reply. Sorry about not being more clear. That photo was taken before I removed the snap ring. The bevel pinion shaft moved about a 1/4” with the snap ring removed, but couldn’t go any further with me removing it by hand.
I like your idea about using the gasket maker. That would be a nice and easy solution. Can that be applied to the outside of the now installed seal where the seal meets the shaft?

 

[hagrid]

How damaged is the collar? From the drawing it appears that collar is responsible for maintaining lash. It shouldn't spin so the damage is puzzling.

 

[softwrangler]

How damaged is the collar? From the drawing it appears that collar is responsible for maintaining lash. It shouldn't spin so the damage is puzzling.

Hi Hagrid. Here’s the closest snapshot I can get of it. The collar seems structually sound. I bet if I could get a solid seal that kept the gear oil from leaking, then the collar wouldn’t pose any other issues. I’m with you on the puzzle. I’m not sure how that could have happened in that spot.

 

[xrocketengineer]

Hi Hagrid. Here’s the closest snapshot I can get of it. The collar seems structually sound. I bet if I could get a solid seal that kept the gear oil from leaking, then the collar wouldn’t pose any other issues. I’m with you on the puzzle. I’m not sure how that could have happened in that spot.

If I understand right, I think that it is not a damaged collar, I think that is the nut staked in place. The adjusting collar is behind the snap ring. I would check for radial play on the shaft and if it is excessive (causing the leak) then the bearings might need to be replaced.

 

[whitetiger]

As was stated before, that is just a nut that is staked as part of the assembly process. The seal just sets on the input shaft.

 

[softwrangler]

Hi Guys, Thanks for your responses. I didn’t realize that the nut was staked as part of the assembly process. Makes perfect sense now that I have read up on it, rather than something being damaged in that obscure place.

I will check the radial play of the shaft and ensure it doesn’t seem to have too much play. But I am now wondering if I somehow damaged the seal when installing it? I think I might order another one and give it another try, assuming the radial doesn’t have too much play.

I appreciate all of your help.

 

[softwrangler]

As was stated before, that is just a nut that is staked as part of the assembly process. The seal just sets on the input shaft.

One last question, do you know how far back the oil seal should sit on the shaft? Is it supposed to go all the way back against the nut? Or should it be set a bit back so as not to be worn or damaged by the staked nut?

 

[hagrid]

Looks like you drive it flush with the counterbore:

 

[xrocketengineer]

I would check the seal for damage. Before seal installation, I would wrap the shaft splines on electrical tape to prevent the splines from scoring the seal.

 

[softwrangler]

Got it. Thanks guys. That is the mistake I made. I drove the seal too far back, probably causing damage to it. Great idea abt the electrical tape. I’ll give it a shot.

 

[whitetiger]

Got it. Thanks guys. That is the mistake I made. I drove the seal too far back, probably causing damage to it. Great idea abt the electrical tape. I’ll give it a shot.

As stated, the seal goes in until it is flush with the counter bore. If you have not already done so, clean all the rust off of the shaft and inside of the housing first.

 

[GeoHorn]

Remember…. The oil seal should be faced open-cup TOWARD the nut to keep oil INSIDE.
It should not be forced so-deeply as to touch the collar which is upset to prevent the nut from rotating on the shaft. I doubt anything has loosened.
Check the shaft splines for damage which might damage the new seal as it’s installed. Also a little grease on the cleaned shaft may help the installation slide over the splines without damage.

 

[softwrangler]

That worked! Thanks again everyone. I appreciate your advice and help.