Changing front axle to gear oil question

[CausticUrbanCoast]

Sorry for my ignorance but does this mean gear oil is more likely to be contaminated with water than UDT over time?

That is what the specifications say:

ISO VG 46 (Agri UDT) is specified to not emulsify when exposed to water and is viscosity stable at all its full temperature range.

SAE will emulsify when exposed to water/condensation and is viscously stable at a specific temperature range and is derated outside that range.

Emulsifying when exposed to water is both a good and bad thing; you instantly know when something is leaking or cracked and that is a very good thing to know!

 

[loggin]

That is what the specifications say:

ISO VG 46 (Agri UDT) is specified to not emulsify when exposed to water and is viscosity stable at all its full temperature range.

SAE will emulsify when exposed to water/condensation and is viscously stable at a specific temperature range and is derated outside that range.

Emulsifying when exposed to water is both a good and bad thing; you instantly know when something is leaking or cracked and that is a very good thing to know!

Good to know. Thanks for clearing that up for me!!

 

[Beeenvenue]

That is what the specifications say:

ISO VG 46 (Agri UDT) is specified to not emulsify when exposed to water and is viscosity stable at all its full temperature range.

SAE will emulsify when exposed to water/condensation and is viscously stable at a specific temperature range and is derated outside that range.

Emulsifying when exposed to water is both a good and bad thing; you instantly know when something is leaking or cracked and that is a very good thing to know!

In fact, gear oils are designed to NOT emulsify with water. The water should stay separate.

Heres are good article to explain most of this The Ultimate Gear Oil Guide - SKF RecondOil

 

[CausticUrbanCoast]

In fact, gear oils are designed to NOT emulsify with water. The water should stay separate.

Heres are good article to explain most of this The Ultimate Gear Oil Guide - SKF RecondOil

Gear oils emulsify and then separate again (they do not homogenize), as I said they are helpful and show when you have an issue right after use.

From your link:

"Low emulsion formation

Gear oils, more than almost any other commonly used oil, need to emulsify water in order for it to be removed from the gears. This means that oils which easily emulsify with water, as opposed to separating from it, are highly undesirable.

This quality is usually maintained through the use of additives. By separating from water, instead of allowing the liquid to emulsify within it, gear oils can rapidly address the problem to keep corrosion and oil oxidation to a minimum.

This is much more important for industrial applications than in automotive ones for obvious reasons.
"

Hydraulic oil will just separate and give no indication that there is a problem, if left long enough it will rust where the water is sitting.

 

[Texasmark]

My 6530 IS a 2007 model and the manual specs HTD fluid. I tore up my front ball bearings in a stupid mistake and refilled with 85W-140 since I live in Tx. otherwise would have been the lighter gear oil....no problems since. I bought a 2016 2400 and the manual and even the fill plug had 85-90 Gear oil specified. I think that Branson for one realized that HTD fluid has it limitations.

 

[rScotty]

Some Kubota's (mine included) use a separated axle and final drive configuration where the final drives are lubricated with lubricant separately from the axle and have their own fill, level and drain plugs and those also get gear oil, not just the axle casting. Not sure which models have a separated cavity and which don't. I see some also have Alemite (zerk) fittings to lubricate the king pin and upper seal and some don't. Mine does. Kind of wish my tie rod ends had grease fittings as well as I just replaced one this spring and OEM tie rod's aren't cheap.

Ah, yes... thanks for reminding me that I bought a grease needle to be able to put grease into the tie rod ends on our Kubota M59.... but then I didn't get around to doing it. Sounds like your M9000s have similar steering. These are all pretty much at the light weight end as far as commercial duty tractors - but that is no excuse not to have grease fittings on the tie rod ends.
rScotty

 

[Unclewillie]

Hello everyone; I have been considering changing my front axle from UDT to gear oil. Either 80w90 or 75w90 synthetic. The manual says that I can use 80w90 as a replacement.
My question is do I have to flush out the UDT and then do a final fill with gear oil or can I just drain and fill with the gear oil and have the small amount of UDT left in the bottom
of the hubs just mix with the new oil?

Any comment on procedure and/or grade would be greatly appreciated

Drain the old and put in the oil.

 

[rScotty]

Yes, using a gear oil for the front axle is the best practice. Oils are more different than they appear. Gear oils don't do the same job as engine oils or trans/hydraulic (UDT) oils, and all are a lot different than single purpose hydraulic oils (HTD). A recommendation to use Hydraulic oil or HTD fluid in the front axle of a 4wd is probably a misprint.

 

[4570Man]

I put gear oil in my tractor front end. My skid steer and mini x call for gear oil in the final drives.

 

[4570Man]

Yes, using a gear oil for the front axle is the best practice. Oils are more different than they appear. Gear oils don't do the same job as engine oils or trans/hydraulic (UDT) oils, and all are a lot different than single purpose hydraulic oils (HTD). A recommendation to use Hydraulic oil or HTD fluid in the front axle of a 4wd is probably a misprint.

Nope, hydraulic oil is spec for Kubota front ends.