Needs some help. Leak in front hub.

   / Needs some help. Leak in front hub. #1  

lzicc

Platinum Member
Joined
Jul 20, 2009
Messages
723
Location
Pittsburgh, Pa
Tractor
Kubota B2650
I have a BX22 that I am having issue's with. The front left axle is leaking gear lube. What would cause this? Do I just need to replace a seal or is there a reason that would cause the current seal to start leaking? Is the seal very hard to change? I ordered a shop manual and am waiting for it to arrive.

Also, as I was checking out it I noticed when I push one of the front tires either back or forth, the axle shifts back and forth like is very loose. What would cause that? I look underneath and the only think I can see the axle is attached to is the steering wheel and the power steering rack and on the front of the axle, there is one nut with a split pin. Is this I guess the pivot point? Would it be as easy as tightening up that nut? I also noticed that there is no play if it is 4 wheel drive.

Any help would be appreciated. Thanks.
 
   / Needs some help. Leak in front hub. #2  
Search around here, there have been a LOT of leaks from that front pivot. Some guys have lost the seal, some people report seepage when using SUDT, gets better if gear oil is used.

But there were also some cracked castings on the early BX front axle housings.

My 04 BX has not leaked at the pivot (using gear oil). My front wheels can be moved when the tractor is off, but get "solid" when the hydraulics are running.

You need somebody better informed than me to look at it. Shouldn't be hard to find :)
 
   / Needs some help. Leak in front hub.
  • Thread Starter
#3  
The pivot is not leaking, it is the left axle end. It's where the axle goes vertical right before it goes to the hub. I did do some searching and didn't really find anything on my particular model.

The pivot point problem isn't that it is leaking, the front axle is loose and the only place I can see where to tighten it is from the pivot point bolt in the middle of the front of the tractor. Not sure if that is all I need to do or if I should be looking somewhere else to tighten it.
 
   / Needs some help. Leak in front hub. #4  
The pivot point problem isn't that it is leaking, the front axle is loose and the only place I can see where to tighten it is from the pivot point bolt in the middle of the front of the tractor. Not sure if that is all I need to do or if I should be looking somewhere else to tighten it.

That pivot bolt is supposed to be adjusted periodically. It's a Goldilocks adjustment - not too loose, not too tight, just snug.

Attached is assembly drawing for hub on a BX. Hope this helps.
 

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  • Front Axle.pdf
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   / Needs some help. Leak in front hub. #5  
Hi Izicc,

I just went through this last week on my BX22. Pulled it apart and turned out I had a cracked casting. When rdaustintx talks about the pivot I'm sure he is refering to the rotation point (where the drive gear case swivels on the bevel gear case) where the front wheels turn cw or cc as the steering wheel is turned. There is a 2 part seal there that can leak.

Getting it apart and back together was pretty easy. Kubota built a very service friendly machine. Clean it up BEFORE taking it apart to save yourself the pain of cleaning up bits of dirt from the inside of the cases. I think the only tools you need to get the whole job done is a 12,14,17mm wrench and a good pair of circlip removal pliers.

Drain the oil from the axle. Pull the tire off, and loosend the drive gear cover bolts (6 bolts, it's just easier when it is attached to the tractor). Then separate the drive/bevel gear case from the axle (4 bolts, don't damage the o-ring when you take it apart) and take the whole thing to a bench to work on.

Once on the bench, unbolt the drive gear case cover (6 bolts) and use the pry notches to get it off. There are two dowel pins so each side must come off evenly and be careful not to scratch the mating surfaces up. Then you have to cock the drive gear and gear case cover a bit to get the gear and cover to clear and come out (it's a puzzle of sorts). Set the drive gear and cover aside.

Look into the drive gear case. There is a circlip that holds the bevel gear case into the drive gear case. Don't worry about getting the circlip past the gear, just get it off the bottom of the bevel gear case. Then pull the bevel gear case out of the drive gear case.

Inspect the drive gear case just above center behind where the bevel gear case would be. That is where the most stress is on the casting and where mine cracked. It will look like just a hair line crack in the paint that follows the curve of the casting. If you think you see a crack, look on the inside of the drive gear case and see if the crack goes through (a mirror and flashlight help to get a good look).

If you see no evidence of a crack, just replace the seal ($20 for the seal. Both sides, one in the drive gear case the other on the bevel gear case are included) and see if that fixes it. Don't destroy the drive gear case seal too bad if possible because it is handy to use when tapping the bevel gear side of the seal onto the bevel gear case. And take note of how deep the drive gear case seal is driven into the casting.

There was a bit of metal in my gear cases probably due to the lack of fluid changes. If there are no big chunks, just clean it as best you can. Clean up the mating surfaces with some brake cleaner etc, apply liquid gasket to the drive gear case cover (note the groove on the drive gear case, this holds liquid gasket so it becomes an o-ring of sorts) and the drive gear case and reassemble. Then clean and apply grease to the bevel gear case o-ring and reassemble it too. Give it over night for the liquid gasket to cure then refill with oil.

If you want pictures of the crack or any other help, let me know.

Jeff
 
   / Needs some help. Leak in front hub. #6  
Let me know if you want the parts diagrams. I'll have to wait until this evening when I get home to post it.

Jeff
 
   / Needs some help. Leak in front hub.
  • Thread Starter
#7  
Thank you, that helps allot. If you do have pictures, I would really appreciate seeing them.

It is hard to explain where it is leaking since I don't know the proper terminology, but I have attached a jpeg from RDS's pdf with the part circled that is leaking. I need to clean up the axle and dry it up and try to get a good look at it to see exactly where it is leaking, like from the bottom or top, etc.

The axle itself I was surprised that I was able to put a little pressure on the tire itself and see the complete axle shifting back and forth as much as it was. It seemed like allot. So tightening up that center bolt should fix that then? This is common I guess? You can feel the axle shifting when driving it. It almost makes a clunk sound when it shifts.

BTW, thank you all for the input. I am new to the Kubota and this really helps.



Hi Izicc,

I just went through this last week on my BX22. Pulled it apart and turned out I had a cracked casting. When rdaustintx talks about the pivot I'm sure he is refering to the rotation point (where the drive gear case swivels on the bevel gear case) where the front wheels turn cw or cc as the steering wheel is turned. There is a 2 part seal there that can leak.

Getting it apart and back together was pretty easy. Kubota built a very service friendly machine. Clean it up BEFORE taking it apart to save yourself the pain of cleaning up bits of dirt from the inside of the cases. I think the only tools you need to get the whole job done is a 12,14,17mm wrench and a good pair of circlip removal pliers.

Drain the oil from the axle. Pull the tire off, and loosend the drive gear cover bolts (6 bolts, it's just easier when it is attached to the tractor). Then separate the drive/bevel gear case from the axle (4 bolts, don't damage the o-ring when you take it apart) and take the whole thing to a bench to work on.

Once on the bench, unbolt the drive gear case cover (6 bolts) and use the pry notches to get it off. There are two dowel pins so each side must come off evenly and be careful not to scratch the mating surfaces up. Then you have to cock the drive gear and gear case cover a bit to get the gear and cover to clear and come out (it's a puzzle of sorts). Set the drive gear and cover aside.

Look into the drive gear case. There is a circlip that holds the bevel gear case into the drive gear case. Don't worry about getting the circlip past the gear, just get it off the bottom of the bevel gear case. Then pull the bevel gear case out of the drive gear case.

Inspect the drive gear case just above center behind where the bevel gear case would be. That is where the most stress is on the casting and where mine cracked. It will look like just a hair line crack in the paint that follows the curve of the casting. If you think you see a crack, look on the inside of the drive gear case and see if the crack goes through (a mirror and flashlight help to get a good look).

If you see no evidence of a crack, just replace the seal ($20 for the seal. Both sides, one in the drive gear case the other on the bevel gear case are included) and see if that fixes it. Don't destroy the drive gear case seal too bad if possible because it is handy to use when tapping the bevel gear side of the seal onto the bevel gear case. And take note of how deep the drive gear case seal is driven into the casting.

There was a bit of metal in my gear cases probably due to the lack of fluid changes. If there are no big chunks, just clean it as best you can. Clean up the mating surfaces with some brake cleaner etc, apply liquid gasket to the drive gear case cover (note the groove on the drive gear case, this holds liquid gasket so it becomes an o-ring of sorts) and the drive gear case and reassemble. Then clean and apply grease to the bevel gear case o-ring and reassemble it too. Give it over night for the liquid gasket to cure then refill with oil.

If you want pictures of the crack or any other help, let me know.

Jeff
 

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  • Axle.jpg
    Axle.jpg
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   / Needs some help. Leak in front hub. #8  
Izicc,

The area you circled was where my leak showed up. Started small, but got bigger to the point where there would be a good pint on the floor each morning due to the crack getting bigger. The oil seemed like it was coming from the seal (see attached, part 050 on the diagram of page 86). Even the dealer thought it was just the seal, and in fact replaced it 3 times before giving up and sending it home.

It took some time to get really bad, but eventually it did. Some really heavy lifting help to speed the process :D.

But as you will see by looking at the pictures, it was definately a cracked casting. I wasn't sure where the problem was when I got ready to tear it apart, so I ordered all the bearings, seals, and the bevel gear casting (of course it turned out to be the drive gear casting instead..:mad:)

Picture 1 is one end of the crack.

Picture 2 is the other end (kinda hard to see in this picture, but it runs all the way down to the left side of the picture following the curve of the casting).

Picture 3 & 4 are the inside of the casting. If you look just left and just right of the center of the pictures you can see to black spots where the casting had chipped away. Zoom in on those spots and you can see and follow the crack from one side of the picture to the other. It was hard to see initially, but the black spots clued me in on where the crack was on the inside.

The last picture is to give some perspective on where the crack is on the casting. In fact if you look to the left side you can get a better view of what picture 2 was trying to show.

The other attachment is a few pages of the parts manual.. The casting cost about $130 from Coleman Equipment in KS, so just hope it is only the seal that needs replaced.
 

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   / Needs some help. Leak in front hub.
  • Thread Starter
#9  
JNJ, that is like finding a needle in a haystack. How did you figure that one out? This really helps allot, now I know what to look for.

Thanks for the detailed explanation and pics. Hopefully this weekend I am going to get the axle cleaned up and dry so I can try to locate where the leak is coming from.
 
   / Needs some help. Leak in front hub. #10  
Well after 3 seals, and it was still leaking really bad, I figured that either the bearings were shot and caused the seal to get torn up or there was a casting problem. Those were the only two places oil could come from in that location.

I had planned on checking the bearings and if they weren't bad, and if I didn't see anything obviously wrong with either of the castings, I would replace the castings one at a time. That is why I purchased the bearings and the cheaper of the two castings. In the end I will send all the bearings and the bevel casting back since none of them were bad.

One other thing to note.. When reassembling you need to be careful to get the bevel gear shaft (part 120, pg 87) into the female bevel gear and bearing (parts 100 & 110, pg 87). It ended up being easier for me to remove the horizontal bevel gear, bearing, and shims (parts 100 110 120 & 130, pg 86) so I could get my fingers in to help align things correctly. The bearing was a bit tight but I was able to use the axle shaft to wiggle it out.

Good luck.

Jeff
 
 
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