Mixing UDT and Gear Oil

GeoHorn

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M4700DT, LA1002FEL, Ferguson5-8B Compactor-Roller, 10KDumpTrailer, RTV-X900
May 18, 2018
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Texas
If you are going to drain it completely, your best bet would be the gear oil in the long term because it will cut down on leaks. Additionally, you need to remove the two "vent plugs" (one on the top of each wheel gearbox) and fill each side to that level to ensure no air in the system. Then replace the plugs and recheck the level with the dipstick and add more oil if necessary.
My M4700 came from the factory with SUDT in the front axle. I recently drained it and changed to 80/90 gear oil. Now the front left axle seal is leaking gear oil on the floor. I’ll have to open the axle and replace a seal. No big deal….and I DON’T think it was gear oil that caused a leak… The amount of SUDT in that front axle was less than a quart when I drained it. I believe my tractor was just like so many others….UNDERSERVICED…. and the SUDT level was so low it was below the seal (about halfway up the pivot on the left side.)
I believe that adding the required amount of gear oil (8 qts) simply brought the level up above that leaking seal and has exposed the fact that seal needs to be replaced. (In fact…. if the axle had been serviced to the proper level …the seal may have been lubricated and not suffered this failure.). IMO
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whitetiger

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Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
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Kansas City, KS
All Kubota tractors come from the factory with UDT or SUDT 2 in the front axle. None come with 80/90 in them.
 
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Njtool

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Lx2610 HSDC. BH77 backhoe
Jan 1, 2021
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New jersey
The dealer puts the fluid in so it is whatever the dealer decides. On my 50 hour service I drained my front axle of gear oil and out in SUDT. That way it’s the same as the hydro and I won’t have to buy another product. Not to mention that I always have extra SUDT on hand.
 
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Nicfin36

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L2501 HST, BH77 Backhoe, SSQA Loader ZD1011 Mower
Jun 19, 2019
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Decatur, AL
The front axle comes prefilled to the dealer, Kubota decides and they use only UDT or SUDT2.
I don't know, I think they come with some oil, the dealer is supposed to top them off when prepping the tractor. Mine was several quarts low on my L2501. Others have had similar issues.
 

whitetiger

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Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
2,542
1,059
113
Kansas City, KS
I don't know, I think they come with some oil, the dealer is supposed to top them off when prepping the tractor. Mine was several quarts low on my L2501. Others have had similar issues.
Yes, the dealer is supposed to check & top off the fluids. Most dealers don't check the tractor, they just check the boxes on the PDI sheet.
I only set up and PDI when the service/repair jobs are slow, so I am very familiar with the process.
 

Henro

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B2910, BX2200, KX41-2V mini Ex.
May 24, 2019
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North of Pittsburgh PA
I picked up my new LX2610 today and the dealer told me more than once that they use gear oil in the front axle and Udt2 everywhere else.

also, in my experience with Jeeps, gear oil has a distinct smell. Not sure how much it varies from hydraulic fluid though.
The issue with this is the question of what KUBOTA puts in to begin with. My understanding is that KUBOTA puts SOMETHING in the front axle before the tractor is shipped. Although they may not put enough in and it may need something added upon delivery. AND that it is UDT or SUDT to keep fluids the same at the factory.

But in reality, as someone said previously, it may make no practical difference. It is not a HST system, just simple gears that need lubrication.

Edit: posted before reading the rest of the thread...but still I guess this comment is relevant...
 

Horst

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Bx23s
Oct 23, 2021
3
0
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Canada
For anyone who cares, I finally had some time today to change the front axle oil.
What came out of the axle was definitely not gear oil, as it was much thinner then the gear oil the dealer had sold me. I'm fairly certain it was UDT or SUDT2 as others have suggested in this thread.
I drained all of it and "flushed" some premium UDT through it before refilling it with premium UDT. Now it's at the right level and I know for sure what is in it :)