SUDT

SkyPup · Apr 18, 2006

( I was told by the 2 local dealers that I dont need the SUDT the reg UDT will be fine because the SUDT is only needed for arctic temps. has anyone heard that before )

We never encounter arctic temperature down here in Florida but we always use SUDT or a SUDT compatible hydraulic fluid in all our GST and HST machines.

If you have a manual transmisson, you don't need it.

N80 · Apr 18, 2006

Why is it so hard to get cold hard data on this stuff? The lack of reliable info is what makes this such a difficult subject.

Here is the paradox:

1) Like many of us, I'm a relative newcomer to tractors and I've just spent more on this tractor than I can believe. My 50 hour service is coming up. I don't have to change the stuff again for another 350 hours which in my case might be 5 or 6 years. So why not just go ahead and get the good stuff, it only costs a little more.

2) There is no objective difference (in terms of actual performance) in UDT vs SUDT that _anyone_ can really show me. My tractor is a manual and even though it gets used hard, it will probably take 5 or 6 years to put 350 more hours on it. It is hot where I live. So why spend around $175 on SUDT when I can put UDT, which Kubota 'makes' and recommends, for about $115 and never know the difference? A fool and his money are soon parted right?

In the end, ignorance will likely cause me to go with the SUDT. And I hate making decisons based on fear and ignorance.

My dealer is having a big sales event this weekend (barbecue, door prizes, factory reps, etc) so I'm going to head over there and see what their take on the matter is.

BandDcabinet · Apr 18, 2006

My dealer says the Kubota SUDT is produced by Valvoline for Kubota. Says he has the MSDS safety sheets for both and the Kubota sheet shows valvoline as the manufacturer. I know I've come across this before somewhere on the internet. Dealer doesn't carry the Kubota oil and is reluctant to order it. Seems to be one of the largest dealers in the area. Kubota must know that he doesn't order their oil. If it's critical why wouldn't they enforce the requirement.

I agree with most here... I'm going to order the Kubota SUDT and not worry about it.

Berniep · Apr 18, 2006

When I did the 50 hour on my BX23 the dealer did not have enough SUDT and not ANY UDT for me to do the change. The parts guy sold me some labeled for John Deer. I was a little reluctant but he said it was the same stuff and met all the specs so I bought it. It made the transmission louder, it whined mor especially when it warmed up(of course it could be that my little bota just don't like green /forums/images/graemlins/grin.gif). Now as it turned out, after about 5 hour I remembered that I forgot to check the pickup screen, I had the perfect excuse to change it again(no honey, it's all gonna drain out and you can't put it back in). Now it's back to being the relativly quiet transmission that it was before.

SkyPup · Apr 19, 2006

There is no comparison between UDT and SUDT, UDT is a straight 30W, whilst SUDT is a 5W-30 multigrade.

N80 · Apr 19, 2006

I understand that they are different, but what does that mean to me, or anyone else, in terms of tranny (manual and HST) and hydraulic performance? Is it strictly a weather issue?

Even if we concede that SUDT is _somehow_ superior, I want to know where, when and how it is superior. And if the superiority is such that there is no comparison, why would Kubota put their name on and recommend the use of UDT in their owner's manuals.

And why, in the owner's manual, do they not describe the proper application for each of their two recommended fluids? That fact alone breeds suspicion. Usually if something is more expensive _and_ worth it, someone can show/tell you why.

SkyPup · Apr 19, 2006

In hydraulic performance and HST & GST trannys, it simply means that SUDT is always superior to UDT.

SkyPup · Apr 19, 2006

Click the attachment and make your own choice!

/forums/images/graemlins/laugh.gif

cart99 · Apr 19, 2006

( I understand that they are different, but what does that mean to me, or anyone else, in terms of tranny (manual and HST) and hydraulic performance? Is it strictly a weather issue?

Even if we concede that SUDT is _somehow_ superior, I want to know where, when and how it is superior. And if the superiority is such that there is no comparison, why would Kubota put their name on and recommend the use of UDT in their owner's manuals.

And why, in the owner's manual, do they not describe the proper application for each of their two recommended fluids? That fact alone breeds suspicion. Usually if something is more expensive _and_ worth it, someone can show/tell you why. )

I can't think of a situation where a multi-viscosity lubricant (i.e. SUDT) would *not* out-perform single-viscosity (UDT)

N80 · Apr 19, 2006

( In hydraulic performance and HST & GST trannys, it simply means that SUDT is always superior to UDT. )

Ah, that clears things up. I guess that's why they call it 'super'.

As for the graph, thanks. I don't know what it means but the super udt line is higher than the udt line so it must be better. But seriously, that is good solid objective data, and that helps.

But this question remains: if sudt is always better in every way, that means udt is always inferior in every way. Why would Kubota, any dealer or any owner ever make it, stock it, sell it, or use it?

Here is what the cynical side of me thinks: UDT is perfectly sufficient for virtually all applications and conditions since it is recommended by Kubota and Kubota does not specifiy when or where SUDT will actually improve performance or protection over UDT. Plus, I'm pretty sure they come with UDT in them. And while SUDT has the potential to provide some theoretical benefit, it is unlikely to be objetively evident regardless of the machine, use or weather.

Here is what the less cynical side of me thinks: SUDT has 'super' in front of it and UDT does not, plus SUDT costs more. And since I only want 'super' stuff in my tractor, that's what I'm going to put in it! /forums/images/graemlins/grin.gif

SkyPup · Apr 19, 2006

SUDT is specifically for use in their modern (made in the last 5-6 years) HST and GST transmissions and hydraulic systems.

If yours is older than that, use UDT, unless you are in Alaska or Canada, then use SUDT for the improved low temp performance.

MessickFarmEqu · Apr 19, 2006

( Plus, I'm pretty sure they come with UDT in them. )

Everything ships with Super UDT.

Marooned · Apr 19, 2006

Another Question (while we're on the subject):

If SUDT is not synthetic, would a synthetic hydraulic oil that meets Kubota's specs be better than the SUDT? /forums/images/graemlins/confused.gif

I was considering going with full synthetic? (Such as Amsoil or somthing similar.)

newcountry · Apr 19, 2006

( But this question remains: if sudt is always better in every way, that means udt is always inferior in every way. Why would Kubota, any dealer or any owner ever make it, stock it, sell it, or use it?)

Kubota probably makes it for the same reason Wal-mart sells engine oil for 89cents a quart - because someone will buy it. I think I know what you're getting at - If Kubota really felt so strongly about SUDT they wouldn't even offer UDT. I say, this is capitalism at it's greatest. I would always rather have more choices for me to choose than have companies make those decisions for me.

( Plus, I'm pretty sure they come with UDT in them. )

What?? That's pretty conspiratorial. /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif

SkyPup · Apr 19, 2006

Amsoil's Full Synthetic Hydraulic fluid is excellent, as is Chevron's and PetroCanada's.

N80 · Apr 19, 2006

( Everything ships with Super UDT. )

Well, that makes a little more sense to me. (My dealer suggested otherwise but I trust what you're telling me). And, if it comes with SUDT in it, then that's what I'm going to put back in it.

My B-I-L farmer uses the synthetic Amsoil in all his eight large tractors. How does its cost compare to SUDT? How do its advantages compare with SUDT? You don't have to change synthetic motor oil as often, is this true with tranny/hydro fluid? I can't imagine going more than 400 hours before changing it, but if it is truly safe to go 500 or 600 and synthetic might really be worth it.

So many choices, so little knowledge (on my part.)

Spiffy · Apr 19, 2006

We had a similar discusion on the PT forum recently, discussing single vs. multi vs. specialty vs. synthetic......

I'm fairly convinced, things like SSLs or PTs etc, cause temp rises even nastier than a hydro tractor; so the parrallel is indirect but interesting.

Anyways, the multis will maintain a tighter viscosity, however, often at the expense of foaming and shear abilities (these do apply more to motor oils [often having high detergent rates too] used as hydro oils than the specialty oils like SUDT). It seemed to follow that if you have high ambient temps (Florida, Texas, etc) the single viscosity would be great, but the data I looked at would imply the need for ISO100 rather than ISO68.

To deal with temp swings [on paper anyway] the synthetics showed the best combinations of stable shear and viscosities, while the multi-viscosity dinos definitely held viscosity better than singles [and should by definition].

Sooooooo? For the questions here: If you like synthetics, do that. If you like your 'bota dealer or have a good source for 'bota products I'd run whatever you think it came with [unless temps dictate Super]. If you like your Deere or NH deeler better, the specs on Deere and HyTran oils looked pretty good (though the info on SUDT and UDT is so vague, it's hard to tell which actually compares better to other oils - for that reason, maybe everyone should boycott (S)UDT until Kubota publishes some specs /forums/images/graemlins/tongue.gif ). Judging from the fact one user in this thread noticed subpar performance with Deere, I have to wonder if the SUDT isn't a higher viscosity than Deere or the mechanic took the Deere oil from the wrong barrel.

SkyPup · Apr 19, 2006

The synthetic is much more resisitant to heat and subsequent oxidation and shear, which is why I use it.

My 55 galon drum of Amsoil's Synthetic Hydraulic fluid cost me about $850 delivered, which was much cheaper than I could acquire the SUDT for....... /forums/images/graemlins/wink.gif

N80 · Apr 19, 2006

Hmmm, my tractor holds 11 gallons. It will need to be changed every 400 hours which for me will likely be about every 6 years. A 55 gallon barrel would provide 5 changes, five changes x 6years equals 30 years! If I'm alive then I'll be beating the average male lifespan.

Seriously though, the improved heat resistance does appeal to me. It is frequently (usuallly) 90+ around here in the summer when my tractor will be used most. Time for more research. I could probably just go in with my B-I-L for a barrel or something a little smaller. He may get some sort of bulk discount too.

SkagitStan · Apr 19, 2006

I'm confused. If I read the chart correctly, after 30 minutes, the available flow rate is almost identical between the 2 oils. What, other than temperature, causes the flow rates to converge?

If temperature is the only variable, then I'd think the graph should indicate the starting (or ambient) temperature, and oil temp required to reach the 30 minute flow rate.

If the chart is based on ambient of -10F, then it isn't particularly relevent to my climate. If it's based on 30F, then maybe it is useful in my climate.

If available flow rate at low temp is the main advantage of SUDT (which is what my dealer tells me) (Are they right?) then what's important to me is how long the oil takes to get to safe operating temp in my normally mild western WA. climate.

If there are other important differences, please tell me what they are! My tractor may be $15K, and I sure don't want to trash it. BUT, my tractor is $15K, which leaves that much less for unnecessary luxuries like spending on oil that isn't shown to improve its health or life. /forums/images/graemlins/confused.gif