B7510 Front Axle Fluid Type?

[NoJacketRequired]

Front axle is a little low on fluid. Bottom ends of the vertical portion of the shaft are weeping a little fluid so I suspect this has been going on for a while and nobody has bothered to top up the axle.

The manual says to use either the same fluid as the hydrostatic transmission (Super UDT I seem to recall) or 80W90 gear oil.

I'm tempted to drain whatever is in there and install Valvoline synthetic 80W90 because it's less likely to be as drippy as hydraulic oil would be, but that's only my uninformed supposition.

What say the great experts here - hydraulic fluid or 80W90, and why?

 

[MadMax31]

I used UDT2 at my 300 hr service. Dont overfill like I did, i forget how,much it holds, pretty sure its listed in my manual. Next time Im up Ill look it up quick. Being immobilized is killing me...

 

[North Idaho Wolfman]

Front axle is a little low on fluid. Bottom ends of the vertical portion of the shaft are weeping a little fluid so I suspect this has been going on for a while and nobody has bothered to top up the axle.

The manual says to use either the same fluid as the hydrostatic transmission (Super UDT I seem to recall) or 80W90 gear oil.

I'm tempted to drain whatever is in there and install Valvoline synthetic 80W90 because it's less likely to be as drippy as hydraulic oil would be, but that's only my uninformed supposition.

What say the great experts here - hydraulic fluid or 80W90, and why?

You probably won't believe this, but the viscosity of the 2 are very close if not the same by spec.

I would have just use UDT in everything!

 

[NoJacketRequired]

Thanks for the helpful suggestions. I just picked up a pail of the Super UDT yesterday and am going to be going outside to do a fluid change in a few minutes. I also purchased the Kubota-branded engine oil (cheaper than buying non-Kubota oil elsewhere) and all six filter elements. Who would have thought this machine has six filter elements on it?!?! The filters cost more than the hydraulic and engine oil.

 

[MadMax31]

I spent close to $300 doing a " 50 hr service " at 300 hrs. All filters, fluids and engine oil. It gave me piece of mind as I didn't know previous owners maintainence practices. Did the coolant as well. Wipe a little old fluid on new filter o-ring surface for smooth install and leak free service.

 

[85Hokie]

NIW,

"You probably won't believe this, but the viscosity of the 2 are very close if not the same by spec."

this may be true at a temperature close to 100 c - most all oils, once very hot will "pour" about the same, more or less, however the SuDT-2 will pour much easier at a colder temp,

straight from Kubota:

Viscosity @ -40º C, cP 16000

Viscosity @ 100º C, cSt 8.1

Viscosity @ 40º C, cSt 37




where as a "typical" 80w-90 has the following:

cSt @ 100ºC 14.5

cSt @ 40ºC 139

as you can see the fluid (S-udt2) will flow much easier while "cold" - and thus as seals start to wear in any given tractor - will leak easier than the typical 80w90 oils.

Many people stick with the heavier oil (80w-90) do to it's ability to stay in place....................when cold !!!!!!!!!!!!

 

[North Idaho Wolfman]

85Hokie,

Yes I was talking in the case of UDT and Reg 80w90

But if you reread he was comparing SUTD-2 and Synthetic 80w90 so still about the same.