UDT or SUPER UDT ?

[First one]

Book say either one can be used in my tractor. Super UDT is alittle more money then the UDT.
I know stupid question, whats the diff? and what would you use? thanks

 

[timswi]

Book say either one can be used in my tractor. Super UDT is alittle more money then the UDT.
I know stupid question, whats the diff? and what would you use? thanks

Super is generally for colder weather...I use it regardless.

 

[jlrsn]

I personally use Super UDT in my Kubota L39 as I live in a very cold climate up at 8,000' in the Rockies and the Super UDT was developed for cold climate operations. The price difference is not that much. If you can get your hands on SAE Paper 972788 it goes into the development of SUDT and the benefits of the Low-Temperature Fluidity of SUDT vs UDT. Before I read the SAE Paper on SUDT I copied the following from a Google search:

The SAE paper basically explains why Kubota was forced to upgrade their UDT specs to Super UDT. Mostly it is due the major advances in their tractor hydraulic equipment over the last ten years or so, especially with hydrostatic transmissions, electronic solenoid actuated gear selection, and the much higher pressures and closer tolerances generated with the new hydraulic pumps. The fact that the hydraulic oil is called upon to perform so many different functions in a wide variety of different equipment applications is also a major factor for Kubota' new hydraulic fluid specifications (which in Japan and some places in Europe is also biodegradeable as well).

The main concerns Kubota addressed were low temps, viscosity and filtration, and extreme pressure-friction.

Even though two oils are of the same viscosity at various temperatures, this does not insure their filtration properties at the various temps, mostly due to differences in wax formation and water contamination which leads to filter blocking.

The Kubota OEM hydraulic filters have a 35 micron filtration ability (their diesel fuel filters have an 8 micron capacity for comparison). This new hydraulic filtration specification is due to a dangerous situation which can develop prior to the hydraulic oil warming up to proper operational temps before use of hydraulic equipment, ie there is severe backpressure at the filter unit until the oil warms up, thus leading to either no or not enough oil in the hydraulic pump. This condition leads to excessive friction and pump destruction.

Use of Super UDT would be a good bet for HST and GST hydraulic systems, especially in colder climates and/or tractors stored outside where condensation buildup in hydraulic fluid is a major concern, as even a 0.5% contamination with water is enough to seriously degrade hydraulic fluid performance.

 

[bp fick]

jlrsn, thanks for the lengthy reply and information.

Old timers here may be bored to death with the udt/sudt conversation, but sometimes folks forget that newer owners come aboard and this is hot new topic for them.

SUDT is simply the natural progression of advancement in lubrication technology. As machinery gets more advanced, the lubricants required must keep up. The idea that sudt is merely for colder weather is a bit of a misnomer and comes from the nifty snow flakes found on the labeling. The thought was to graphically represent better cold temperature flow rate. How well that worked out for Kubota in communicating sudt's properties, I don't know.

Frankly, I suspect within 5 years, the need will exist for a much improved sudt and there will be a re-formulation or even a new name altogether. As expensive and complicated as these hydro units are and seeing how much we demand of the hydro systems, advancements in superior fluids will be a must.

 

[sw03]

Book say either one can be used in my tractor. Super UDT is alittle more money then the UDT.
I know stupid question, whats the diff? and what would you use? thanks

I know you are new here but use the search function..This is beaten over and over since 2002

 

[jlrsn]

This subject probably has been beaten over and over since 2002 but is new to many new and old members. I don't understand why someone has to always tell someone to use the Search Function. What was new a few years ago won't hurt anyone from learning or re-learning again!!

I've been twisting wrenches professionally since the mid-50s and I can always learn except from the know-it-alls that don't know anything but think they do.
Have a nice day,
Jim

 

[coobie]

This subject probably has been beaten over and over since 2002 but is new to many new and old members. I don't understand why someone has to always tell someone to use the Search Function. What was new a few years ago won't hurt anyone from learning or re-learning again!!

I've been twisting wrenches professionally since the mid-50s and I can always learn except from the know-it-alls that don't know anything but think they do.
Have a nice day,
Jim

Good post,I agree.coobie

 

[mustangsallysdad]

This subject probably has been beaten over and over since 2002 but is new to many new and old members. I don't understand why someone has to always tell someone to use the Search Function. What was new a few years ago won't hurt anyone from learning or re-learning again!!

I've been twisting wrenches professionally since the mid-50s and I can always learn except from the know-it-alls that don't know anything but think they do.
Have a nice day,
Jim

Agreed! We should use this format to help one another with whatever advice (good or bad experiences) we can dispense. As was stated earlier, SUDT isn't just for cold climates...if you love your hydro, it's cheap insurance. Help us teach an old dog some new tricks!

 

[firefighter jim]

I agree also, if they don't like a new post asking an old question, don't read it!

 

[First one]

Thanks guys, for not turning on me for asking an old question I don't know if I'd ask anything else , if you had of.
We new owners (and old)look to you all to learn things we don't know .
From tips on how to do things right or wrong. Hearing that someone took the time to answer you back on a question means someone cares enough to help . Thanks again!!