HST Transmission Oil

Smokeless

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Any intel what type transmission fluid/oil comes in these Kubota 3901? thanks
 

85Hokie

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I would bet S-UDT2..... and I would use nothing but... IMHO

Now having said that...........I am gonna AssUme that it is an HST?????

If stick, I would not guess - even though S-UDT2 there too.
 

Smokeless

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I would bet S-UDT2..... and I would use nothing but... IMHO

Now having said that...........I am gonna AssUme that it is an HST?????

If stick, I would not guess - even though S-UDT2 there too.
Guess I miscued, yes HST 3901. Ok, Super UDT it is, thanks
 

random

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Checking my manual, (L3301 / L3901) it specifies Kubota Super UDT-2.

Manual 2wd - 28L / 7.4gal
Manual 4wd - 28.5L / 7.5gal
HST - 23.5L / 6.2gal
 

BobInSD

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Possible Thread Highjack:

Is there a problem with keeping a partially empty 5-gallon jug of S-UDT around, given temperature swings of +90 to -20? I just got my 2012 HST, and don't need any fluid but want some on hand for when it does. I'm not anticipating a fluid change $oon, so will probably just be topping off as implements/loader are disconnected and reconnected. (I haven't found any actual leaks yet, but it's only been 26 hours).

Buy a gallon, or buy the big jug which it may be years before I use?
 
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85Hokie

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Guess I miscued, yes HST 3901. Ok, Super UDT it is, thanks
It is $$$ stuff - but it did make a huge "whiny" difference when I replaced my hydraulic oil in my BX.....
 

Nicfin36

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I did my 50 hour service yesterday and replaced my hydraulic oil with UDT2. I did this for two reasons. The first was that it had mostly UDT in it as I had a fitting spin loose and the dealer gave me a 5 gallon bucket of UDT. So, I knew it had mostly UDT in it already. Several here say they come with UDT2, I mentioned that to the salesman and he said it has UDT in it. I didn't argue. But, are these tractors being filled by the dealer when they are uncrated? If so, I bet many use cheaper UDT than UDT2 and owners are running tractors assuming it is UDT2. So, I just drained mine when I changed filters and added UDT2 so I know for sure.


Possible Thread Highjack:

Is there a problem with keeping a partially empty 5-gallon jug of S-UDT around, given temperature swings of +90 to -20? I just got my 2012 HST, and don't need any fluid but want some on hand for when it does. I'm not anticipating a fluid change $oon, so will probably just be topping off as implements/loader are disconnected and reconnected. (I haven't found any actual leaks yet, but it's only been 26 hours).

Buy a gallon, or buy the big jug which it may be years before I use?

Google says the best storage temperature is between 32 and 77F. I would just keep a smaller jug handy rather than a 5 gallon bucket of it. The only time you would need 5 gallons is if you had a malfunction of some kind dumping all your oil. If I had a partial bucket though, I would just hold onto it. I would be worried more about water getting in it over time more than anything.

I'm not a big believer in oil going bad over a reasonable time frame. If that was the case, it should go bad in the tractor.
 

BobInSD

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Yeah, I was mainly wondering about condensation with air in the jug and temp swings. I can keep it in the house, I guess. Then it would actually pour if I had to add some on a below 0 day.

Thanks,
 

Nicfin36

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Yeah, I was mainly wondering about condensation with air in the jug and temp swings. I can keep it in the house, I guess. Then it would actually pour if I had to add some on a below 0 day.

Thanks,
I was going to suggest keeping it inside, but wasn't sure that was an option. If you have a smaller empty jug, you could pour it into that and keep it inside. But, I have 2 year old (Shell) hydraulic fluid with about a gallon left in it and it looks like new. It rarely reaches freezing temps here with short periods in the teens. As long as the bucket has the cap on it, I really don't see a problem with an appreciable amount of moisture getting in. Any small amounts of moisture will be vaporized in the tractor when the fluid gets hot running it anyway. Storing it off the ground would possibly help minimize moisture.
 

RCW

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Yeah, I was mainly wondering about condensation with air in the jug and temp swings. I can keep it in the house, I guess. Then it would actually pour if I had to add some on a below 0 day.
Don't keep hydraulic fluid in the house.

The main concern is the tanks/reservoirs IN a tractor are open to the atmosphere (e.g., vented). Same for the fuel tank, HST tank, etc.

As temperatures change, the fluid in those tanks/reservoirs expand and contract, inviting humidity into your tractor's tanks/reservoirs, causing condensation (water) in the tractor .

Your SUDT2 jug on the shelf is not vented. If the fluid gets hot, the jug swells, if it gets cold, the jug retracts.

Don't sweat a sealed jug on the shelf in an unheated spot. Just keep it dry.

I've got a 2.5 gallon jug out in my unheated garage now..... :cool:
 
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Smokeless

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I did my 50 hour service yesterday and replaced my hydraulic oil with UDT2. I did this for two reasons. The first was that it had mostly UDT in it as I had a fitting spin loose and the dealer gave me a 5 gallon bucket of UDT. So, I knew it had mostly UDT in it already. Several here say they come with UDT2, I mentioned that to the salesman and he said it has UDT in it. I didn't argue. But, are these tractors being filled by the dealer when they are uncrated? If so, I bet many use cheaper UDT than UDT2 and owners are running tractors assuming it is UDT2. So, I just drained mine when I changed filters and added UDT2 so I know for sure.





Google says the best storage temperature is between 32 and 77F. I would just keep a smaller jug handy rather than a 5 gallon bucket of it. The only time you would need 5 gallons is if you had a malfunction of some kind dumping all your oil. If I had a partial bucket though, I would just hold onto it. I would be worried more about water getting in it over time more than anything.

I'm not a big believer in oil going bad over a reasonable time frame. If that was the case
I did my 50 hour service yesterday and replaced my hydraulic oil with UDT2. I did this for two reasons. The first was that it had mostly UDT in it as I had a fitting spin loose and the dealer gave me a 5 gallon bucket of UDT. So, I knew it had mostly UDT in it already. Several here say they come with UDT2, I mentioned that to the salesman and he said it has UDT in it. I didn't argue. But, are these tractors being filled by the dealer when they are uncrated? If so, I bet many use cheaper UDT than UDT2 and owners are running tractors assuming it is UDT2. So, I just drained mine when I changed filters and added UDT2 so I know for sure.
It is $$$ stuff - but it did make a huge "whiny" difference when I replaced my hydraulic oil in my BX.....
Heard the whine business before. Well i guess i will try the expensive stuff and hopefully all will be better.

Gonna show my ignorance here, am guessing drain hst transmission at each drain plug, then remove filters......reverse operation. Make sense????
 

85Hokie

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Heard the whine business before. Well i guess i will try the expensive stuff and hopefully all will be better.

Gonna show my ignorance here, am guessing drain hst transmission at each drain plug, then remove filters......reverse operation. Make sense????

Makes perfect sense - I think despite the cost, you will be pleased with the new oil and the lack of sounds.
 
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RCW

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Makes perfect sense - I think despite the cost, you will be pleased with the new oil and the lack of sounds.
I don't know if an "L" follows a little BX, but I've changed mine at 50, and twice since then, and I'm at 400.

Each time I change it the HST whine has decreased greatly.
 

wgator

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Smokeless, if your tractor actually came from factory with SUDT2, doubt you will notice any difference in HST sounds. That being said, I will use SUDT2 in my L4701 every change until Kubota comes out with a "better" hydraulic fluid than SUDT2.
 

Nicfin36

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As to the whine, I just used the tractor for the first time since draining and filling with UDT2. My observance, the tractor did not whine like it use to. The first few minutes was actually very "quiet". However, after the tractor heated up, I notice the whine a bit more. I think it is still a bit quieter than it was with the old fluid. So, I think there is some truth to people claiming the whine is less with UDT2.

I will also add that since my tractor whined like that the whole time before the change, it probably had UDT in it and not UDT2.
 

Smokeless

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As to the whine, I just used the tractor for the first time since draining and filling with UDT2. My observance, the tractor did not whine like it use to. The first few minutes was actually very "quiet". However, after the tractor heated up, I notice the whine a bit more. I think it is still a bit quieter than it was with the old fluid. So, I think there is some truth to people claiming the whine is less with UDT2.

I will also add that since my tractor whined like that the whole time before the change, it probably had UDT in it and not UDT2.
Well i will give it a shot and see where it takes me. There is a part of me that realizes the whine is an engineering decision rather than a lubrication fix.......recognizing we must have good lubricants. Thanks to all for posting, I am better informed
 

Nicfin36

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Don't expect anything spectacular. I just wanted the best fluid for my tractor. I really wasn't doing it for sound reduction, but it does to appear slightly less whiny than it used to be.
 

RCW

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I am not sure I follow this. I keep my pail of S-UD2 in the basement of my house where the temperature never changes much. What is the risk here?
My apologies. I should have been more explicit. There is no risk.

I was picturing someone keeping a 1 or 2.5 gallon container in their kitchen to avoid temperature variations.

It's just not necessary to keep it in "the house" for that reason.

I keep mine in an unheated, attached garage without worry.

Again, the jugs are not vented. I don't see an issue as to where they're stored, as long as its dry.
 

Smokeless

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Checking my manual, (L3301 / L3901) it specifies Kubota Super UDT-2.

Manual 2wd - 28L / 7.4gal
Manual 4wd - 28.5L / 7.5gal
HST - 23.5L / 6.2gal
I breezed past this somehow, will have to check my manual,. Dont recall it specifying Super UDT-2, Thanks