Oil question for front axle

[oosik]

For the front axle gear case and front differential case - I use 80/90 gear oil. Kubota also recommends - UDT and Super UDT fluids. I've had two tractors in the 40+ years out here. Always used 80/90 gear oil in the front end. Never had a moments problem with either tractor.

 

[John_Mc]

Don't know if you can use a Synthetic or not. I don't see why not, there's no synchronizers in there, AFAIK. No 'yellow metals'...... Right? (Synthetic gear oil is hard on 'yellow' metals)

Actually it's not whether a lube is synthetic or not that makes it hard on yellow metals. Some lubes, both synthetic and non-synthetic are engineered to be safe with yellow metals, some of each type are not. I use an Amsoil full synthetic transmission oil in the transmission of my antique truck, since I wanted a lube that would best protect the freshly rebuilt transmission and it's synchronizers. This one is safe for use with yellow metals. The same company offers others that are not.

 

[Gord Baker]

Only 1 choice here. Consider the replacement Cost of front end drive. Follow Manufacturers recommendations.

 

[Username Taken]

Only 1 choice here. Consider the replacement Cost of front end drive. Follow Manufacturers recommendations.

OEM's will not recommend better stuff than what they use as Factory Fill.

When they buy Lubricants, they buy them by the truckload or rail car. They also don't know where the tractor/truck/car/whatever is going to be used so they go with a generic, all-around lube. It also helps that they can save several thousands of dollars.

In a high end car, like a Ferrari or a Lambo, they're Factory Filled with Synthetics. The very best they can find.

But we're buying an over-priced status symbol, we're buying a tool, a workhorse.

That's why I take OEM recommendations with a grain of salt. They're good to know but that's about it.

If I lived in a Hot, Hot part of the Country I might consider running a high viscosity gear lube in my Kioti Front end. If I used it every day and worked its tail-end off, I'd also consider it. But for most of us in here, I'd just use what Michigan Iron says to use. A good Hydraulic Fluid.

 

[mcmopar]

Actually it's not whether a lube is synthetic or not that makes it hard on yellow metals. Some lubes, both synthetic and non-synthetic are engineered to be safe with yellow metals, some of each type are not. I use an Amsoil full synthetic transmission oil in the transmission of my antique truck, since I wanted a lube that would best protect the freshly rebuilt transmission and it's synchronizers. This one is safe for use with yellow metals. The same company offers others that are not.

What are yellow metals? I can't recall ever hearing that term before.

 

[Deanes]

Hoping there might be an oil expert that can answer this but if kioti factory filled my front axle with hydrolic oil could I not use this ATF when I do thee 50 hour service? I was always under the impression that ATF was superior to hydraulic fluid and wasn't used simply cause of cost. I have 3 crates of thiss ATF and no use for it. I also have a crate of synthetic 80-90 but feel that the viscosity of ATF would flowView attachment 782846View attachment 782847 better and lubricate the axle turning spindles better as they are integral to the axle.

Honestly, other than warranty issues, I expect anything would work in a front axle. I had a final drive in an old mower that leaked oil, so just filled it with gun grease. I figured if anything in there needed more lubrication it would begin to heat, and melt enough grease to flow. Ran it that way for 12 years.

 

[piper184]

IIRC yellow metals are either brass or bronze which is copper combined with either zinc or tin? In transmissions and axles usually bushings or synchronizers. Some additives can attack the elements zinc or tin and "pull" them out of the part in question. It is a slow process but it can do damage. Fluids that are "yellow metal safe" have different additives.

Years ago Chrysler used ATF in SOME manual transmissions, not all. I never knew the reasoning behind it but it worked. Most of their manual transmissions used 80W-90.

Older heavy equipment like the CAT D7 I used to operate used 30W straight weight engine oil for hydraulics, but it was specified Non-detergent only.

I have also read/heard that ATF is just as good as regular hydraulic fluid, but it is more expensive because it has lots of additives for transmissions that are not needed in a system that is hydraulic only. I have used it in a pinch when needed with no ill effects. I don't think there is any issue even when mixing it with hydraulic fluid. I would never do this where hydraulics and trans share the same fluid simply because I don't know the consequences.

One time I did an experiment with a bunch of different fluids of different grades and weights. Put them in baby food jars about half full and set them outside in the cold. I could tip the jars and observe the viscosity. Not very scientific but I was curious. As the temps dropped below 0F they all started to look pretty much the same but you could still detect some differences. Except for the 80W90, which was like honey at that point. At -20F there was very little observable difference and even less at -33F, which was as cold as that experiment got. I was trying to determine what flowed easiest in a really cold hydraulic system, nothing else. ATF while less viscous at room temps surprisingly stiffened up faster than I expected.

The ATF that the OP is asking about is probably just fine for his front end but I am no expert. At today's prices and lack of availability in some places, it is completely reasonable to look at options.

Manufacturers and dealerships have their own reasons for recommendations. They are not always in the best interest of the customer or his bank account.

Lubrication chemistry is a career all in itself. For us "regular people" we have to sift through what information we can find and make the best educated (not indoctrinated) decision we can.

 

[RobbyG]

Hoping there might be an oil expert that can answer this but if kioti factory filled my front axle with hydrolic oil could I not use this ATF when I do thee 50 hour service? I was always under the impression that ATF was superior to hydraulic fluid and wasn't used simply cause of cost. I have 3 crates of thiss ATF and no use for it. I also have a crate of synthetic 80-90 but feel that the viscosity of ATF would flowView attachment 782846View attachment 782847 better and lubricate the axle turning spindles better as they are integral to the axle.

I purchased my first 50hp Ditchwitch w/ front mounted backhoe in 1982. I was told by the Ditch witch dealer that even though the books called for Hydraulic oil in the systems that I could use 5w motor oil in its place. That is what I used in place of hydraulic for that and all following pieces of equipment I have owned. The 5w oil can be ordered from a lubricant dustributor and is usually cheaper than hydraulic oil.

 

[RobbyG]

I purchased my first 50hp Ditchwitch w/ front mounted backhoe in 1982. I was told by the Ditch witch dealer that even though the books called for Hydraulic oil in the systems that I could use 5w motor oil in its place. That is what I used in place of hydraulic for that and all following pieces of equipment I have owned. The 5w oil can be ordered from a lubricant dustributor and is usually cheaper than hydraulic oil.

Make sure to order %w non detergent motor oil.

 

[John_Mc]

remember that the "80w90" of gear oil is on a different scale than your engine oil - 80w90 is similar to 20w50 engine oil, as far as viscosity goes:
View attachment 782920

@ning is exactly right here.

A couple of years ago, I was serching for the best lube to use in the recently rebuilt transmission transmission of my antique truck. A company which specializes in the restoration of these old trucks (and is highly respected in this segment of the antique vehicle world) recommended Amsoil SAE 50 Long-Life Synthetic Transmission Oil. He used it for it's excellent lubricity, wide temperature tolerance, and long life, while also being safe for yellow metals. I filled my truck's transmission and transfer case with it.

I had several second thoughts when a couple of mechanic friends pointed out that the 1950's era shop manual for the truck recommended 90 weight gear oil. They were concerned the something that was "only SAE 50" would not have the required viscosity.

I contacted Amsoil tech support to ask about this concern. Here is what I heard back:

Our SAE 50 Long Life Synthetic Transmission Fluid is actually rated as a crankcase fluid, because that is what most of the applications that it is used in will call for. When rating as an SAE Gear Lube it would be considered a 90 weight gear lube, also being a GL-1 it would be safe with yellow metals. So it does fit the specifications for what your transmission is asking for.

I further mentioned that if it was the equivalent of a 90 weight gear oil, I was surprised that it shifted so much easier than the 90 weight gear oil the previous owner had in the transmission- especially in colder temperatures and before the transmission had warmed up. His response to that comment:

Being that our fluid is 100% synthetic it does not surprise me that you have easier shifting in cold weather as our fluids are designed to perform better in extreme environments, both cold and warm. Our SAE 50 Long Life Transmission Fluid is a straight weight fluid, so it is not a multi viscosity. So it would be comparable to a straight 90 weight gear lube.

The "W" in multi viscosity rating literally stands for winter, as that is when it will be a thinner viscosity so it flows easier. For example, a 75W-90 will be a 75 weight gear lube in cold weather and once it get closer to operating temperature then it acts like a 90 weight gear lube. That is why a 75W-90 is typically used as a replacement for something needing a 90 weight gear lube.