How soon is soon enough for Super UDT2 in Front Axle ?

DieselBound

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Aug 9, 2016
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2,816
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Arlington, WA
Tractor
Kubota B7800; Kioti NX5510HC
Kioti says regular gear oil (sorry, don't have the weight spec in my head) OR hydralic fluid: not sure what it says in my Kubota manual. I suspect that regular gear oil was in the front axle. I see no way that SUDT could turn to that color w/o having some signficant damage, likely seals (what else could impart black/dark like that?), but that would seem to result in an external sign of leaks. Without knowing what the dealer used one cannot say for sure.

I drained the fluid out of my B7800's front axle (trying to remember whether I'd ever done so [was good about everything else]) and I am sure that it didn't look dark like that. And mind you, we're talking a LOT more hours; and, I doubt that anyone has worked a tractor harder than I've worked this B7800 (I won't go into describing what I've done because people will start sniping away that it's "abuse").

If you haven't sent a sample to the lab yet I'd recommend making a note that you're not sure what fluid that is (probably OK to state that it could be either one or the other).
 

Red Eye

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Jan 29, 2011
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22
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Kamloops B.C.
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kubota L6060, JD Model A, Grader, Excavator, Dump Truck, Harley Softail, KTM 500xcw
Same use as me, and my bearings in the front end failed twice in 4000 hours. Now I run a 1500 lb ballast box and no more dirty oil or failures.
 

alpha&omega

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Jun 18, 2020
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SWM
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John Deere - 3046R/3038E Kubota - B3200
A couple caveats to what other have posted. First, as @BeezFun mentioned, the use of Blackstone Labs was the first thing I thought about when you mentioned metal in the front axle fluid. I have used those guys for testing the Tranny fluid, Diff Fluid and the Engine oil in my Denali as well as the oil in Grand National. They are a reputable company, very professional and pride themselves in their work.
Second, @Williy brought up a point that also came to mind. Are you the first owner of this tractor? How many hours were on it when you bought it? Could someone have put something like “Royal Purple” gear oil in the front end, which would be obvious reasoning behind the color. However, this would not explain the metal shavings. After it settles out, if it looks more like a metal milkshake than gear oil that has metal shavings in the bottom of the container, then I would be worried. If it were the latter of the two and this was the first time the oil had been changed, it wouldn’t be a complete shock because of the initial break in of the gears. Add in the fact that you have not been using a ballast box and that only adds more shavings and stress to the front end.

The two big questions I have for you is are your rear tires loaded (Rim Guard or otherwise) and does your front axle have a vent/breather tube (either somewhere at its highest point or built into the dipstick). Having owned both Kubota’s and Deere’s I have had issues with the front axles leaking as a result of high pressure. The recommended gear oil heats up and begins to build pressure within the housing; with nowhere to go it finds the weakest point - the rubber gasket for the wheel bearings - and viola a leak develops. This leak can in turn allow water to enter the housing via rain or moisture build up from the outside ambient air. Since water has a higher boiling point than gear oil and because the two don’t mix well the water will boil off (especially in 4WD), thus increasing the wear on the front end.
I’m not saying this or any of the other things I previously mentioned is your issue, but rather its something to be aware of, especially considering you already have a potential lingering problem.
Did you run any cleaner or new fluid through the front housing? With the front end lifted up, you can add some new/clean gear oil into the axle housing, slowly rotate the front wheels and then drain it. Do this once or twice to see if there is any additional sediment you may have missed. A couple good neodymium (rare earth) magnets near the drain plugs will help to collect any shavings. This will give you an idea as to how bad the problem is without tearing things apart.
If I had to guess the front axle fluid hasn’t been drained by the dealer and wasn’t changed until now, add the lack of rear ballast during front end work and hopefully that’s the cause for your wear. In either case, sending the fluids off to Blackstone will give you a good idea and basis for your next change.
In the event Kubota doesn’t “feel the need” to warranty this problem, then I would consider that with the cost of the fluid, you could potentially make draining the front axle an “end of year item” - not just for preventive maintenance but also for your peace of mind. Hopefully this helps. Please keep us posted of your results. Most guys post a problem and then never come back to post their results, which could have helped someone else who is in the same or a similar situation.
 

orezok

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Jan 30, 2004
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2,271
Location
Mojave Desert, CA
Tractor
Kubota B7800
Kioti says regular gear oil (sorry, don't have the weight spec in my head) OR hydralic fluid: not sure what it says in my Kubota manual. I suspect that regular gear oil was in the front axle. I see no way that SUDT could turn to that color w/o having some signficant damage, likely seals (what else could impart black/dark like that?), but that would seem to result in an external sign of leaks. Without knowing what the dealer used one cannot say for sure.

I drained the fluid out of my B7800's front axle (trying to remember whether I'd ever done so [was good about everything else]) and I am sure that it didn't look dark like that. And mind you, we're talking a LOT more hours; and, I doubt that anyone has worked a tractor harder than I've worked this B7800 (I won't go into describing what I've done because people will start sniping away that it's "abuse").

If you haven't sent a sample to the lab yet I'd recommend making a note that you're not sure what fluid that is (probably OK to state that it could be either one or the other).
I too have a 17 year old B7800. I too have abused it well beyond its specifications. Lifting 40% more than the loader specs state. Backdragging with the bucket full dumped. Tilling with a tiller that greatly exceeds specs for HP and weight and in 17 years I have only had 2 repairs. A leaking rear axle seal and a treadle centering bearing. Total cost for me to repair was less than $50.

This thing is a beast.

I do follow manufacture service specs.
 

JRH02

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Oct 3, 2020
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29
Location
PNW, canyons and forest.
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Kub B7100 manual; JD410J
I switched to synthetic gear oil at 50 hours in my past 2 Kubota tractors. At 400h the gear oil looked similar to new oil, perhaps a shade darker, but I didn't so a side by side backlit comparison.

I personally would not worry too much about how dark the sudt2 was in the photo. You could send a sample out for analysis to see how it compares to similar applications that may be on file. I doubt Kubota will give you a real answer, particularly if it involves disassembly to inspect.

On larger stuff it is a given that lube samples will be collected and the results correlated with the data from the Mfr's data on what part is made from what material and what is showing up in the oil. It is a really accurate way to identify what is wearing without a break down for a look see. I just did a full change out on a JD 410j and everything came back pristine. It is the first for the hyd and trans (ten years :oops:) and of course with std intervals with engine oil. The samples are cheap compared to the labor, materials, etc.

But I'm not sure if data is available for smaller units. I have an old B7100 manual that runs great but blows a bit of smoke under load and starts a bit hard in the winter due to compression. I don't bother with samples. If I'm suspicious I just change it out. BTW, its been on Mobile1 for many years. And I run it in everything I have. But for trans/hyd, just the spec petroleum.

But if you do a get a drain out with bunches of metal you know the damage is already done. Its way past the time for the "which part is it question." If any question it is "Am I doing even more damage that need not be by running it anyway?"

It doesn't sound good. The best you can do at this point is to shorten the change outs.
 

JRH02

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Oct 3, 2020
Messages
29
Location
PNW, canyons and forest.
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Kub B7100 manual; JD410J
My thoughts jump to how positive are you that the dealer actually changed the axle oil in the first place?
Whether on a pickup or a working machine its pretty easy to tell if a drain plug has just been pulled. Just seeing a new filter, it there is one, doesn't cut it. You have to crawl under it and look. If a mechanic wipes the spot or even put a tool in it so it looked like it was done, well, there's not much you can do about that. That's why I do my own stuff. For the big stuff I call my SIL who is a Cat mechanic. If he screws up I'll apply a large, in arrears, dowry and cut off his hunting access (wink). But he is a cool guy.
 

alpha&omega

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Jun 18, 2020
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SWM
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John Deere - 3046R/3038E Kubota - B3200
Whether on a pickup or a working machine its pretty easy to tell if a drain plug has just been pulled. Just seeing a new filter, it there is one, doesn't cut it. You have to crawl under it and look. If a mechanic wipes the spot or even put a tool in it so it looked like it was done, well, there's not much you can do about that. That's why I do my own stuff. For the big stuff I call my SIL who is a Cat mechanic. If he screws up I'll apply a large, in arrears, dowry and cut off his hunting access (wink). But he is a cool guy.
Exactly!
If anything of mine needs to go to the stealership for work or a mechanic for that matter, I use a paint marker on the item to be repaired/replaced. This means that the new OEM part that I bought would or would not have been changed out. Same goes for a tire rotation.
 

ljjhouser

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Joined
Oct 25, 2018
Messages
346
Location
Midwest
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Kubota L4701
Glad you posted this. After reading you OP post. I checked my oil. I follow the manual with all work. I called the dealer about the inital filter change. He told me to just check for metal on the magnet - if no metal, clean it and don't change filter. I am 300 hours. I checked my front axle oil and it looks like yours. dark. But no indication of much metal or particles. So I went ahead and changed the oil at 300. Might do it again at 500 or maybe 600 just to keep it clean. The transmission looks clean - hard to see on the dipstick - I will change it at 400 like the manual.
 

quarencia

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Joined
Apr 2, 2007
Messages
99
Location
NW Connecticut
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Kubota BX2230 & B3200
In my experience, ballast recommendations from manufacturers have nothing to do with front axle loading and everything to do with liability from tipping and roll over. That’s why they recommend either three point ballast or loaded tires. There are dealers who won’t sell a loader without three point ballast or filled tires. When I’ve checked on a couple of past tractors I’ve owned, the front axle was rated beyond the applied forces of a fully loaded loader. I doubt ballast is a requirement for the front axle warranty…but I’d have to read the entire warranty to be sure. And how could the manufacturer prove one way or another wether you used ballast? In some specific situations, they may be able to prove overloading thru fracture or metallurgical analysis (of the worn part, not the metal in the oil). Doing that analysis definitively would almost certainly cost the OEM more than replacing the axle. Of course the opposite is true as well. If OE said no to warranty, could an owner afford the analysis to prove it was faulty design/manufacture/maintenance? If I got to the point of having to spend money to try force warranty coverage, I’d probably try to negotiate a new axle at cost and install it myself.

And for the record, I always use ballast with a loader. Currently have beat juice in rear tires of my B3200.
 
 
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