Oil & Fuel 50hr front axle oil??

jimainiac · Dec 4, 2009

How can you blame anybody for being a bit confused when the manual calls for either SUDT or 80-90 Wt. gear oil? To the naked eye they couldn't look more different. That decision was above my pay grade, so I relied on the experience and judgement of my dealer. They recommended gear oil, so that's what I went with. It made sense to me, too, as it's good enough for the axles in our pickups.

bp fick · Dec 4, 2009

I did have someone at a Kubota dealer mention that the sudt is in there from the factory, likely, not a fact, but likely just because they have it on the line. Makes sense. The person also said that udt makes for a good break in oil for the front hubs, but again, drain it to get the "flakes" out and replace with high quality gear lube.

These dealership fellows aren't engineers for Kubota, but still, knowledgeable of the tractor and people who do the warranty work and other maintenance on them. I also agree that 4 x 4 truck front axles use gear lube.
All that said, SUDT is pretty fancy stuff, I suppose and quite capable.

dex3361 · Dec 4, 2009

When I recently change the BX1500 it had SUDT and the L4400 had some sort of gear oil. I put the 80w-90w gear oil back in.

DickS · Dec 4, 2009

Not to hi-jack this thread, but does anyone know the actual oil capacity for the front axle?

bp fick · Dec 4, 2009

Dick
Each model tractor is different.

Deano · Dec 4, 2009

DickS said:
Not to hi-jack this thread, but does anyone know the actual oil capacity for the front axle?

I see you have a BX24. The front axle capacity is 5 quarts.

Deano

Baby Grand · Dec 5, 2009

From somewhere on the internets:

... The EP additive system, which includes sulfur-phosphorous, borates and sulfur-phosphorous-boron chemistries, provides a chemically protective film that protects against welding, scuffing and scoring of the gears during boundary lubrication conditions, which can occur at start-up, stopping and high shock loads. The EP lubricant grades correspond to ISO viscosity grades 68 to 1,500. EP gear oils perform well over a wide range of gear drive sizes and speeds in a temperature range of -15oC to 121oC .

IMHO - There seems to be a lot of focus on our tractor front ends being low speed and therefor not requiring EP (Extreem Pressure) additives. But tell me that your front end doesn't see start-up, stopping and high shock loads - I know mine does whenever I give the FEL a good workout. In fact, low speed high torque power transmission is really the classic example of a boundary layer lubrication condition. The gears are not rolling and sliding against each other fast enough to develop the protective hydrodynamic wedge of oil between metal surfaces, and this leads to metal to metal contact. This metal to metal contact is the primary cause of welding, scuffing and scoring of gear teeth. This, and our relatively mild winter temperatures in CT, is why I will be using EP gear oil in my front axle. If you live in an area where you will be using your machine at temperatures below -15 deg C, SUDT is probably the best option. Just my $.02.

-Jim

actionaj · Dec 5, 2009

I ran my 2350 with sudt until the 300 hr. mark and then switched to gear oil. It just makes more since to run the thicker oil, more protection and lessor chance of leaks.

sw03 · Dec 5, 2009

I ran SUDT in front diff and drained...grey and metal flacks...Switched to Amsoil's best......way better and it is made for gears too! LOL

ibnxe · Dec 5, 2009

SUDT is about half the viscosity of UDT, which is about the equivalant of 20 weight oil. As far as I can determine, neither of these oils have any EP (Extreme Pressure) additives. These aren't going to present any real protection against gear gaulling and wear.
I use 80W-90 gear oil, and wouldn't use anything else. On my uneven property, I'm in 4 wheel drive most of the time.