MFWD Axle Oil

[arlen4720]

In the last several years, I've noticed that many tractors are calling for hydraulic oil in the front axle. This seems odd to me. What do you supposed the logic is? I would think 80-90 gear lube would be better, and not as likely to leak. Even though it seems odd, I'm not going to go put gear oil in my front axle...Just wondering why?

 

[abeal]

I think it is a simple way for manufacturers to reduce costs by using one less fluid in production.

 

[Bob77064]

Gear is what I will use when I change mine. Mobil 1 75-90 is what I like.

 

[3930dave]

I think it is a simple way for manufacturers to reduce costs by using one less fluid in production.

And, even in their quantities, a quart of hyd. fluid is cheaper than a quart of gear oil.

I'm with the OP, I prefer a heavier (and for my low temps, synthetic) gear oil in an axle.

But, playing devils advocate, hyd. fluid has been used successfully in gear(stick) transmissions for quite a while.

I'd like to be joking about this, but I won't be surprised if the EPA is pushing off-road equipment OEM's to reduce drive-train losses. Using hyd. fluid in an axle is their cheapest way to accomplish this.

Rgds, D.

 

[Renze]

not hydraulic oil, but STOU (Standard Tractor Oil Universal) which can serve both for hydraulics, engine as well as gearlube. It has best of three worlds, it has anti foam additives for hydraulics, high temperature additives for engines and high pressure additives for gears. The reason manufacturers want it in front axles is that the reservoirs are rather small and its likely to heat up. STOU has both the high pressure capacities as well as the high temperature capacities when this quart of oil to lubricate high horsepower axles heats up on a long working day.

We even put it in wheel loader axles with oil immersed brakes, they run quite hot and standard gear oil doesnt lube at those temperatures.

 

[ray66v]

Both products are not measured on the same scale. If you do the research, you will find the fact is, the hydraulic transmission oils are actually about the same viscosity as the 80w gear oil. And they are interchangeable in this application.

You can also see this, with a visual side by side pour test.

Both are made to lubricate gears. The gear oil is specifically made for the purpose, and if you use a gear oil that has an "EP", extreme pressure, designation it is the best protection available.

The question is, is it really necessary to use the EP gear lube? The truth is, probably not. But, I consider it cheap insurance.

 

[JasG]

Many of the old tractors that used gear oil in the rear ends and trans, the OEM's now recommend trans hydraulic in place of the gear oil.

This also makes it very simple, many of the OEMs try and make service as simple as possible. Cat for a while was using engine oil in there dozers for everything. They even tried to use Diesel for a torque converter fluid. The change to one fluid is to help customers as much as anything, makes for a good selling point that the end user has fewer fluids to stock and less chance of putting the wrong fluid in.

 

[Soundguy]

In the last several years, I've noticed that many tractors are calling for hydraulic oil in the front axle. This seems odd to me. What do you supposed the logic is? I would think 80-90 gear lube would be better, and not as likely to leak. Even though it seems odd, I'm not going to go put gear oil in my front axle...Just wondering why?

UTF or UDT maybee.. but not straight hyd oil?

 

[Soundguy]

i got some older cat stuff that specs 30w and 40w in everything. trans too.

Many of the old tractors that used gear oil in the rear ends and trans, the OEM's now recommend trans hydraulic in place of the gear oil.

This also makes it very simple, many of the OEMs try and make service as simple as possible. Cat for a while was using engine oil in there dozers for everything. They even tried to use Diesel for a torque converter fluid. The change to one fluid is to help customers as much as anything, makes for a good selling point that the end user has fewer fluids to stock and less chance of putting the wrong fluid in.

 

[MHarryE]

My Kubotas specify either Super UDT 2 or gear oil. In general gear oil has EP (extra pressure) additives that are needed for gears with sliding contact but those EP additives are chemically harmful to friction discs. Some front ends have limited slip differentials that have friction discs. We use them at Cat (backhoe loaders, compactors). We use TDTO (transmission and drive train oil) that protects friction discs in power shift transmissions and limited slip differentials but will also work as a hydraulic fluid but is pricier than our hydraulic oil.