UDT or Gear Oil

[Jibber]

I'm literally right in the middle of my 50 hour service on an L3130HST.

I've done everything and am now draining the front axle case. In the manual it says to use Super UDT or UDT.. OR.. 90 weight gear oil.

From the smell and consistency, I'd say that they had 90 weight in there from the factory.

My question: Hydraulic oil is so thin.. and gear oil much thicker. Can they really be interchangeable?

also..what did YOU use and why?

I realize I probably should have posted this in the generic Oil and Lubricants forum, but I'm looking for Kubota owner/operators and a quick response.

Thanks for any advice.. I've got plenty of UDT.. but gear oil would mean another trip to the dealer.

 

[Junkman]

for cold weather use, the Super UDT is better than the 90 weight gear lube in my opinion, which doesn't count for much. The BX series use Super UDT. If your has 90 weight, I would just put back what was in there. If you haven't drained it yet, I would just leave it alone.

 

[Jibber]

Drained.

messy job too. The drain bolts are right over the bottom lip of the wheel..

I'm using funnels trying to catch it and divert it into a drain pan... slow draining too.. further indication it's 90 weight oil.

I'm going to need to take a bath in a degreaser tub to get the oil off me after this one is done.

 

[gsxr1100]

Super UDT has a pour point of –46 C or –50.8 F max. The Amsoil gear fluid (Series 200075w-90) I used in my BX22 has a pour point of –51 F; samething for both

The Super UDTY has a Kinematic Viscosity @ 100°C of 9.00 cst and Amsoil series 2000 has a 15.7 cst. A Kinematic Viscosity @ 40°C is 45 cst for Super UDT and the gear fluid has 113.5.

For me, I like the higher KV and the fact that I wanted gear fluid for my gears.

 

[Junkman]

/forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif What did he say??????? /forums/images/graemlins/grin.gif

 

[Lockport]

He said:

1- Temperature: This parameter effects the process in all steps. It can be modeled by an Arrhenius expression: J = Joe(-Ea/RT). Generally, flux increases with temperature due to kinematics viscosity. Too high a temperature may result in increasing hydraulic resistance.
2- Pressure: As mentioned above, vapor difference is the driving force for pervaporation. The larger the transmembrane pressure difference is, the larger is the permeate flux. However, a large pressure difference can result in no effect or in fouling of the membrane.
3- Crossflow velocity: Within small Reynolds number range, flux can be enhanced by reducing hydraulic diameter or by increasing flow velocity. A critical velocity is necessary to achieve the maximum separation potential. However, in turbulent flow regimes, very small flow effect is observed.
4- Feed concentration: Since overall permeability of a component depends on its solubility and diffusion rate through the membrane, the permeate flux is significantly influenced by feed concentration.

I think /forums/images/graemlins/confused.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/confused.gif

Which I think means that at temps exceeding 100C the Amsoil will have less flux resulting in the least amount of hydraulic flow resistance.

 

[Jibber]

I think I need to go back to school to understand all that. (Physics wasn't my best subject.)

Until then.. I guess I'll just follow the manual.

That way if anything goes wrong.. they can't zap my warranty.

 

[Bird]

My B2710 came with UDT in the front axle, and of course, the manual said to use UDT, Super UDT, or 80W-90 gear oil.

 

[Junkman]

Thanks for the explanation. I bet that you could probably write the formula for catching ghosts in space since you understand this high tech stuff. I almost caught a poltergeist once that was trying to steal my BX, but my hands slipped off of him/her when I tackled him/her since he/she was covered in Super UDT.. /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

 

[Jibber]

I used super UDT.

I'm a ***** when it comes to manufacturers recommendations. PS.. I already had a ready supply of the stuff.

I would like to know, however, what the difference is between Kubota UDT and Super UDT.. considering the price difference. They don't tell you these things. I guess they figure that you will pay more to get the best for your tractor.. but I've never seen anything spelling out why you should go with the Super over the regular UDT.