Super UDT alternative

I have a '13 1140CPX with 770 hours. I need to do the normal maintenance. I just changed the engine oil.
I'm about to change the transmission and hydraulic fluid and filters. I read on here where Chevron All Weather Synthetic THF was the same as Super UDT. I can't find it anywhere, so I broke down and bought 3gal ($85) Super UDT from dealership. My intension is to use it in the tranny and fill the hydraulic tank with a quality grade, non-synthetic substitute.
The hydraulic tank and system is independent of the transmission, correct? My thinking is, and please tell me if I am wrong, the hydraulic system is just the bed tilt and the auxiliaries... correct? If so I rarely use the bed tilt and never have used the auxiliaries thus no need to shoot for the moon on fluid.
Also, do you recommend changing out the knuckle fluid and rear differential. If so, is there a reason that the more expensive fluid is better?

no. the tank is the hydrostat fluid and the bed lift. the gear box is independent but cross contamination is likely. use only SUDT it has been well proven and accepted that these RTV respond favorably to Kubota only fluids and filters for the power train.

I used the sudt2 in my RTV . I did use the John Deere Hyguard in my RTV's knuckle cases when I was out of the standard kubota. but ... they use so little .. why not go with the Kubota ? I seldom used my dump bed so did not change often.. but any hydraulic use and I would be encouraged to go gold (kubota) when I did change. collie.

i think there may be some model confusion. on the 1140cpx and the rtv 1100cw share the same drivetrain and hydraulic system and is a bit different than the 900. on the ops machine there is reference to a hydraulic oil tank under the seat and transmission dipstick and fill on the top of the transmission. the confusion starts here and is kubotas fault in my opinion. in short there is a three speed "GEAR" transmission coupled to a hydro-static drive. the oil in the compartment under the bed on top of the transmission lubricates the three speed "GEAR SET" and uses UDT or SUDT. the tank under the seat provides for the "HYDRO-STATIC DRIVE" and the bed lift power steering. kubota refers this to the "HYDRAULIC SYSTEM" this i believe is misleading people to think that reservoir is just for the bed lift." BIG MISTAKE" i beleive it is important to use the same fluid in both compartments in case of cross contamination to protect the pumps. clear as mud????

aurthuritis,
Are you saying there are 2 separate hydraulic oil reservoirs? If that were the case the oil in the transmission would never be filtered,
I always thought thru some marvel of Kubota engineering, the oil in the transmission compartment was circulated thru
oil cooler, oil tank under seat, and filtered.
If I'm wrong Please correct me.
Dirt
X900

what i am say is we perceive the transmission as one unit that includes gears and pumps valves oil coolers etc. but kubota refers to the gearcase as the transmission and the hydrostat as the hydraulic system. the gearcase is it's own reservoir bathing the gears and differential brakes etc in SUDT. the reservoir under the seat contains the SUDT for the pumps swash plates valves oil coolers and servos etc that make up the hydrostat. the gearcase is unfiltered. the older 900 had a separate reservoir just for the bed lift furthering the confusion. then there are some model specific differences as well.

Thanks to all, especially Mr. Aurthuritus. I'm glad I asked., It is too important to chance. I'll mortgage something and get enough from Kubota to fill the hydraulic tank.
It was interesting, when I bought the SUDT for the tranny, the kid behind counter said it only called for a little less than 2 gals. I asked three times because my manual says 2.9gal. I wonder which is right. They said I could bring back what was unopened. I got extra.

Thanks again!

you are welcome. don't forget the OEM filters. i have been driving through much water and swamps lately so i need to change my knuckle cases and front diff fluid also. it is good to have a little around for top off's and such.

Aurthuritis, which of the newer models have the poorly described fill ports ? I remember several members trashing their transmissions -thinking they had filled their transmissions after a change? collie

i think it has been an issue always. it wasn't until i saw the transaxle unit disassembled until i understood myself. but the design itself is bullet proof as long as it gets proper attention.

just as a side note. if you save the old SUDT that comes out of the compartments and use it in an oil can to lube chains and on plow blades and stuff like that. it has excellent anti corrosion properties

Pretty good on fire ants also...….

We put the used but clean hydraulic oil in our feed wagons oil bath reservoirs too. It keeps the roller chains going smoothly- It has huge gears in the compartment and heavy chain but runs like clockwork. When we bought it used, the previous owner had put used motor oil in there.. Nasty nasty as I had to use a putty knife to scrape it out but now slick and smooth running.

D&D Farm said:

Pretty good on fire ants also...….

Click to expand...

never had any problems with fire ants getting rusty. wink

I think the best fix for fire ants is to pour melted alumnium in their dens. When you dig it out it makes a neat sculpture.