L2550dt front axle problems

[Groo]

So I noticed a oily disc on the ground while loading up some gravel. After looking at it closer I realized it was an oil seal of some sort that match the drive-line color of the Kubota. I pulled it into the garage and began looking around for where it goes. It turns out to be the plug at the bottom of the turning shaft on one side of the front axle.
There wasn't tons of oil in the area of the plug, so I guessing there is some damage.
any pointers on what to look for and what to replace regardless?
how likely is it that the other side is fine?
Any Kubota junk yards out there in case I need a whole front axle?

 

[repete]

Is it the round approximately 3" plug that is leaking? I have a L2550DT and have worked on the front end quite a bit over the first 5500 hours.

 

[Groo]

I don't know if it was leaking before, but I found it on the ground and there wasn't much oil in the area. Wild guess is heat from running relatively dry built up pressure and popped it out.

I am thinking maybe all bearings and seals? I am hoping the gears weren't too damaged.

 

[repete]

My 2550 had no vent to the axle. I drilled and tapped a barbed fitting in the fill plug and ran a hose up to the engine compartment.

 

[Groo]

well, prices all bearings and seals and it came out to about $400. I guess about what I expected, but still some sticker shock. I think I'll do some more investigating before I place the order.

 

[repete]

I would agree. Be absolutely sure where the leak is coming from. I worked for some time trying to cure leaks in the front end and after replacement of seals, I discovered hairline cracks in the bevel gear housings just above where the housing rotates on the axle. The casting at that point was only about 1/8" thick. That was the point where I set my wheels to the narrow position as opposed to the wide position. These housing were about $600 each 15 years ago. I have cracked no housings since. With the wheels in the narrow position, the wheels are centered over the housing as opposed to leveraging against the housings in the wider position.

Where do you live?

 

[Groo]

I would agree. Be absolutely sure where the leak is coming from. I worked for some time trying to cure leaks in the front end and after replacement of seals, I discovered hairline cracks in the bevel gear housings just above where the housing rotates on the axle. The casting at that point was only about 1/8" thick. That was the point where I set my wheels to the narrow position as opposed to the wide position. These housing were about $600 each 15 years ago. I have cracked no housings since. With the wheels in the narrow position, the wheels are centered over the housing as opposed to leveraging against the housings in the wider position.

Where do you live?

these front wheels look like they would not allow a wide-set.

I live on the MI/WI boarder

there is a great deal of grit sitting on top of the bearing exposed by the loss of the plug. Looks like a mix of dirt, burnt oil and metal bits.
The outer stub bearings feel good.
the two gear I could see look worn, but good enough for an old tractor.

I need some more tools to dig in deeper. I'll spend the rest of the day messing with snow.

 

[repete]

You can drain the center of the axle. I would be curious to see how that grease looks.

Do you have the snap ring pliers for the ring to drop the bearing out and check it?

 

[Groo]

I finally got the upper opened up. It was fine. The other side was full of oil when I opened it up. I didn't open up the center, but I suspect it is fine too.
I couldn't get the pivoting section off the upper, even after removing the snap-ring. Not sure If I missed something, but I don't really need to get it off. looks like I got off easy; just the lower bearing on the one side.

Think the cap that popped out on its own is reusable? I'm not sure I can easily get a replacement.

 

[repete]

I finally got the upper opened up. It was fine. The other side was full of oil when I opened it up. I didn't open up the center, but I suspect it is fine too.
I couldn't get the pivoting section off the upper, even after removing the snap-ring. Not sure If I missed something, but I don't really need to get it off. looks like I got off easy; just the lower bearing on the one side.

Think the cap that popped out on its own is reusable? I'm not sure I can easily get a replacement.

I have reused the caps many times. Are there any shims or washers that may have slid into the groove where the retainer ring sits?

 

[repete]

Can you get the bevel gear cover off to check those two bearings as well? There is just a large "O" ring that seals that area and I have reused mine several times. If those bearings are shot then you will be back into the case in the future to replace the same bearing you are replacing today. Also, when you refill the front end with clean grease, be sure to remove the vent plugs to allow grease into the outer part of the axle. The grease has to come down through the tube and fill the wheel area and it will not displace the air.

 

[Groo]

I did check all the bearing on the dry side. Only the bottom one was bad. The rest spun smoothly.

That plug couldn't have been missing too long. I think it was dirt coming up that took out the bottom one, not running dry.

Thanks for the pointer on the outer top plugs. I was wondering why there was a "separate fill port" there when it is a common oil cavity.

 

[repete]

I did check all the bearing on the dry side. Only the bottom one was bad. The rest spun smoothly.

That plug couldn't have been missing too long. I think it was dirt coming up that took out the bottom one, not running dry.

Thanks for the pointer on the outer top plugs. I was wondering why there was a "separate fill port" there when it is a common oil cavity.

Did you understand about the fill plug vent? I drilled for a 1/8" hose barb fitting that would allow me to connect a hose to up under the engine compartment and ran it through a cheap fuel line filter just to get clean air. If you drill a 1/8" hole that comes out along side the vent dipstick then drill and tab just far enough for the pipe fitting you should be fine. I too was rather surprised there was no vent capability, only what breathed around the seals.

 

[Groo]

I was thinking I'd drill the main fill plug for a vent, that way if I mess it up; I'm only out a plug.
I was thinking a bellows breather, just run it up to the top of the hood then loop it, or run it into the clean side of the air filter....but starting to rethink some of that. I wonder if they seal it to keep moisture out of the oil. If that's the case, I'd probably want the bellows or a desiccant or TRAP filter on the breather.

 

[repete]

I figured I would just let it breath air with no restriction. Having mine in a wet environment, I figured it was going to breath by the seals regardless so I just gave it a better place than to suck water.

 

[Groo]

well, I was getting ready to put it together and realized the seal on the pivot joint was crap. Some penetrating oil I was trying to use to clean it up was running out what should have been a sealed joint. I suspect that is likely the root cause of all the problems. I hammered it apart and can better see that the pivot bearings are also garbage. Glad I didn't just slap it together, because it wouldn't have lasted too long before the garbage bearings toasted the new one with their contamination. back to the parts shopping.

 

[repete]

I would pop the other side cap off as well and check it out for contaminates. At least get fresh grease in both sides and drain the pumpkin as well.

 

[Groo]

I drained the other side and picked up 2 gallons of gear oil to top it all off (takes 6.8gts per the book)

 

[Groo]

This job never ends.

I finally get the parts and have some time to work on it, and I either screwed up the seal or got the wrong one. I can not get the two halves together enough to get the snap ring in. I am thinking it is the wrong one.
I even put the outer back on the tractor set it down on a board and then jumped up an down on the bucket. I wouldn't budge, then I start pildriving on it with a big slab or wood, about the equivalent of a RR tie. still nothing.

I was thinking threaded rod might force the two halves together, but the more I think on it, I probably have too big of a seal. I certainly don't want to crack the housings seeing that they are more than $700 each (no matter how much it sounds like that was my goal).

 

[repete]

Are you trying to do it on the tractor or on the bench? Kubota made a change to the seal some years ago after problems with the original. My recollection is that you can remove the 90 degree portion from the axle end and reassemble the unit while upside down. Having done it both ways, I found I had a lot of trouble with the shims that were placed to adjust the bearings. Let me go out to the shop in a bit and check the package part # for the spare I keep on the shelf.

Do not hammer on it.