Kubota UDT for front axle gear oil?

   / Kubota UDT for front axle gear oil? #11  
Several years ago had a lengthy discussion about this here. UDT and 80-90w are very similar in viscosity. I even ran a pour test and verified that to my surprise. :)
 
   / Kubota UDT for front axle gear oil? #12  
Both types of oil would be just fine. If there was any real advantage to either one, the manufacturer would let you know. I run 85W-90 in mine.

On a side note, John Deere recommends running hydraulic oil in the final drives on my dozer. I was a little surprised to see that since final drives can see some pretty harsh punishment.
 
   / Kubota UDT for front axle gear oil?
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#13  
I went with the gear oil due to flash point and viscosity differences. I didn't compare the UDT as stated in the title, I compared Super UDT and Valvoline 80-90. I found the Suoer UDT flash point at 262 and viscosity >22 mm2/s at 40C. The Valvoline flash point was 424.9 and viscosity 146 mm2/s at 40C. I'm not sure if either has an advantage over the other.
 
   / Kubota UDT for front axle gear oil? #14  
I need to change the front differential case and front axle gear oils, the manual says Kubota UDT, Super UDT, or SAE 80-90 gear oil may be used. Anyone have any experience or recommendations on this? The Kubota UDT (equivalent) feels like a lighter oil to me. I'm sure UDT is fine if it's on the manual.

UDT is about 20wt eq, SUDT is about 10wt eq, and 80-90 gear oil is about 30wt eq. If your bezel/axle seals are good, you can run whatever you want. I'm up to 90w-140 myself :)
 
   / Kubota UDT for front axle gear oil? #15  
I read that there will be some condensation on the inside there, using gear oil will separate and you may have ice chunks in the front axle, obviously in a cold climate. We did put gear oil in it for the summer because that's what we had when the 400 hour mark came, but I'm putting udt2 in as it says it will not separate from any water that may condensate in there.
 
   / Kubota UDT for front axle gear oil? #16  
…I'm putting udt2 in as it says it will not separate from any water that may condensate in there…
….curious to see the wording on that. 😉
 
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   / Kubota UDT for front axle gear oil? #17  
i'd go w/either straight GL5 80/90, or Valvoline conventional 75/90 gear oil. synthetic 75/90 ok too, but much pricier. save the udt for hydraulics.
btw you have an awesome tractor...imho pre tier4 M series stands head & shoulders above the rest
 
   / Kubota UDT for front axle gear oil? #18  
80 90w utd is to thin and will not keep bearing lubed like 80 90w will I worked in a machine shop for several years and fixed many gear boxes with thin oil in them 80 90 w fixed all the problems we had
 
 
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