Leak that comes and goes?

aaluck

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L4400HST, Bush Hog 276, RDTH60, Speeco PHD, etc
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I have a leak that comes and goes. Right now it 'comes'--maybe because of the cold weather. To be clear, it leaked (very little) this summer in June/July time frame. I figured that I didn't tighten the drain plug good enough on the last change, so I changed the gear oil again the the leak 'stopped' until last week. AND its way worse than last time. I know this because I would check the tire before every use in the summer, which is at least once a week to mow, usually more. Seemed to have started again after I dug some holes with auger last weekend.

I'm fairly handy and have the workshop manual but feel like this may be a bigger job than I can handle. Can someone maybe tell me how big a job it will be and from the pictures what the problem may be? I'm assuming its the gasket.

Thanks
 

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85Hokie

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Sounds like a seal is going.....going and now gone. What weight oil you using? If UDT - SUDT2 .....you could switch to 85w90 weight..... that is only a bandaid fix however.

You have WSM by chance?

This is on the L4400?
 
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bernhardine

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If you would clean up als parts, you could see where the leak is.

What's about the venttube/vent valve? Is it free or restricted?
 
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rentthis

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If you are handy with tools and have the workshop manual, it isn't a bad job. As 85Hokie said, 90wgt gear oil can correct it for a time. I have had the heavier oil stop it for years. The perfect fix, to me, is a new seal and a refill with 90 wgt. The book likely gives you the option of oils.
 

GreensvilleJay

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in 3rd picture, top center, it looks like the casting is fractured above the 'white hair like' whisker.....
thicker oil isn't the cure of course, the leak needs to be found, then repaired.
 

aaluck

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L4400HST, Bush Hog 276, RDTH60, Speeco PHD, etc
Oct 9, 2019
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you could switch to 85w90 weight
That's exactly what I did in June/July. Which may explain why it went away for a while.

I do have the WSM...just don't know if its something I can tackle.

in 3rd picture, top center, it looks like the casting is fractured above the 'white hair like' whisker.....
I don't see that. When I changed it in the summer I pressures washed it and didn't see anything like that.

Can you point or circle on the photos where you are looking so I can check that out.


If you would clean up als parts, you could see where the leak is.

What's about the venttube/vent valve? Is it free or restricted?
Ill check that.
 

marklbota

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B2710
Jan 30, 2021
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I had a seal leak like that on a New Holland I used to own, it wasn't bad to fix. I didn't need any specialized tools, hopefully kubota is similar. I'd do as suggested, clean it up good and then watch it really carefully so you see where that first drop of oil comes from. If this is happening prematurely, it might help to add ballast to the 3pt if you're doing a lot of loader work.
 
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bearbait

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The trouble is dirt and grit get in around the seal and will cause it to leak. If you have a pressure washer use it to clean it up real good and it's best to do it after each time you have it in mud. If it's been leaking for a long time it may be gone too far for that to work.
 

aaluck

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L4400HST, Bush Hog 276, RDTH60, Speeco PHD, etc
Oct 9, 2019
932
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Snowdoun, AL
he trouble is dirt and grit get in around the seal and will cause it to leak. If you have a pressure washer use it to clean it up real good and it's best to do it after each time you have it in mud. If it's been leaking for a long time it may be gone too far for that to work.
That's what a lot of the videos on you tube seem to say. The problem is I THINK my leak is the next gasket after the knuckle (higher). From the oil spread it seems that way to me at least.
 

bearbait

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That's what a lot of the videos on you tube seem to say. The problem is I THINK my leak is the next gasket after the knuckle (higher). From the oil spread it seems that way to me at least.
Clean it up and keep a close watch on it and if you're right well then I guess it's time to operate, good luck.
 

bearbait

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Lol, I hear ya but there's only one way to learn.
Also check to see if yours has a vent line and if it does pull the fill plug and try blowing through the vent line to make sure it's not plugged. Damn mud daubers will get in the line and plug it. If you use a compressor with not too much pressure you'll be able to hear the air coming out the fill hole, could be just building up pressure if it's plugged, good luck.
 

aaluck

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L4400HST, Bush Hog 276, RDTH60, Speeco PHD, etc
Oct 9, 2019
932
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93
Snowdoun, AL
Also check to see if yours has a vent line and if it does pull the fill plug and try blowing through the vent line to make sure it's not plugged. Damn mud daubers will get in the line and plug it. If you use a compressor with not too much pressure you'll be able to hear the air coming out the fill hole, could be just building up pressure if it's plugged, good luck.
I will. I also looked at the WSM last night and it actually looks straightforward. Four bolts remove, replace gasket, put back on with spines aligned tighten back up. Luckily the front gear case bevel gear case come off together and in one piece.
gearbox.jpg
gearbox.jpg
 

bearbait

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I will. I also looked at the WSM last night and it actually looks straightforward. Four bolts remove, replace gasket, put back on with spines aligned tighten back up. Luckily the front gear case bevel gear case come off together and in one piece. View attachment 54663 View attachment 54663
Good deal, let us know how it goes.
 

rbargeron

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That's what a lot of the videos on you tube seem to say. The problem is I THINK my leak is the next gasket after the knuckle (higher). From the oil spread it seems that way to me at least.
Its almost never the gasket, almost always the large rotating seal. - A in diagram below. (reposted here )

Check out this thread for discussion of how to change it.
 

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aaluck

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L4400HST, Bush Hog 276, RDTH60, Speeco PHD, etc
Oct 9, 2019
932
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Snowdoun, AL
Its almost never the gasket, almost always the large rotating seal. - A in diagram below. (reposted here )
That's what the dealer said when I went to order the other O-ring. I'm going to clean it up real good and see if I can maybe get a better idea. Thanks for the link.
 

lugbolt

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ZG127S-54
Oct 15, 2015
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yeah kingpin seal

I have done a ton of them

not terribly hard to do. I found that taking the outer part of the hub off before taking the kingpin assembly off makes things go easier, about 30 lbs lighter weight. Once off it's just a matter of getting the snap rings out and separating the top and bottom. Use a hammer and don't be afraid to use it, just don't go hammering on or near machined surfaces and you will be fine. There is a nub on the top of the kingpin, you can hit on that just fine and really that's all that's needed to separate it once the snap rings are out. Then just a matter of taking the old seal out and installing the new one. The sea is two piece, a wear ring and the seal. Clean up the rust and dirt around where the seal and ring rides. Apply oil to the inside of the ring and the outside of the seal. Loosely install the seal onto the kingpin. Then just drop the kingpin down onto the part that is normally attached to the front axle housing. Sometimes I did them without removing the housing, just remove the snap ring, knock the kingpin off of the axle (keep up with where the bearing shims go) then replace the seal, using floor jack to push the kingpin back onto the tractor far enough to reinstall the snap ring. Not too bad. Takes me about 4 hours to do both sides including refilling the axle assembly.

when u remove the wear ring, you will find rust under it and I believe that might play a part in leaking. Clean it off good, about all you can do. Use plenty of lube for reassembly of the seal, and it goes right together.

On some tractors the right side hub is shipped not installed to the axle, and the assembly tech has to install it. I've seen once or twice where the o-ring would get cut, but generally speaking they come back within a month-usually less-with owner complaining of a leak. Almost always fixed long before it goes out of warranty.
 
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