Gear oil vs UDT in front axle

ItBmine

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B2620
Jan 21, 2014
958
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Canada
I use Premium (or Super in the USA) UDT in my front axle. And change it every 200 hours or less when I service the hydro.
I went with this choice as I operate in winter weather down to to minus 40*C.

I've spoken to Kubota reps about it and they said I could run either oil, but they leaned towards the UDT for my climate. I know the factory oil I drained out sure seemed thinner than gear oil also.
 

propuckstopper

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GR2010, BX2380
Jan 10, 2018
35
0
6
Canada
I use Premium (or Super in the USA) UDT in my front axle. And change it every 200 hours or less when I service the hydro.
I went with this choice as I operate in winter weather down to to minus 40*C.

I've spoken to Kubota reps about it and they said I could run either oil, but they leaned towards the UDT for my climate. I know the factory oil I drained out sure seemed thinner than gear oil also.
I use Amsoil Severe Gear 75W-90 in my BX 2380 front axle. It seems to work just fine. I can't say that it works any better than UDT (how would you really know?) but I have had good luck with synthetic gear oils in race cars.

I realize a tractor is far from a race car, but I had the oil on the shelf so I used it. I also have it in the front axle of my GR.
 

RCW

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BX2360, FEL, MMM, BX2750D snowblower. 1953 Minneapolis Moline ZAU
Apr 28, 2013
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I also use SUDT2. About half of my tractor hours can be winter with the blower, so I thought something lighter might be a good idea.

I think the coldest I’ve used the blower was -8F.
 

ItBmine

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B2620
Jan 21, 2014
958
10
18
Canada
From Wiki. I'm just south of White River.

White River advertises itself as "The Coldest Spot in Canada" with recorded temperatures as low as −58 °C (−72 °F). However, this is a myth, as the coldest temperature in Canada was recorded in Snag, Yukon, at −62.8 °C (−81.0 °F) on 3 February 1947
 

RCW

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Then you really wouldn't like our minus 40, LOL
We've been -35F or so rarely, but thankfully the old "too cold snow" theory usually applies.

The exception here is the notorious "lake effect" off from Lake Ontario and Lake Erie. We're kinda near the edge of it depending on wind direction....we don't get hit even close to what Tughill Tom sees.

Lake effect is driven by wind and wind direction (NW/W): TTom can be at 0F and windy, plus get snow in FEET...ugghhhh...
 

RCW

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If you raised that temp 30 F ..... I still want NO parts of that!:p:ROFLMAO:
Getting to the point where I'm not sure I want to deal with it either, but it's all I've known.

Heck - - there's times where 22F feels warm... couple years ago February our average temp for the month was 9F....
 

Tractor Gal

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Oct 30, 2020
50
3
8
NC
I put 80W90 in my L2501 front axle. The manual says UDT or 80W90 gear oil is fine for mine as well. The most important thing is to have one or the other rather than NONE. Mine had virtually none in it when I checked it. A very common problem it seems as incompetent dealers do not properly fill them when they prep the tractor.

I think you would be fine with either one. Since I'm in the south, I chose to use 80W90 as cold will never be a factor.
"The most important thing is to have one or the other rather than NONE. Mine had virtually none in it when I checked it. A very common problem it seems as incompetent dealers do not properly fill them when they prep the tractor. "

Sadly, this seems to be the situation for this tractor...all fluids are low or empty, poor job of greasing, leaks, missing pins or snap rings, electrical wiring is shot, on an on. When will I learn that "you get what you pay for?" OTOH, I think in the long run, this will turn out to be OK as these things get addressed in this tractor. The engine seems strong so that would be the most important to me. I can do these little things, although I find it amazing that a dealer would let a tractor go out in this condition. Another lesson that I continue to need to re-learn...don't believe everything you're told! :)

But, I would be remiss to omit the fact that I am learning a lot about this tractor. That's a plus. I've never had hydraulics so this is an all-new area. Hopefully, I'll be able learn enough to have some enjoyment, as well as safety, in using this to do a few things that can't be done by hand. Like most things...it's a process.

TG
 
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lugbolt

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ZG127S-54
Oct 15, 2015
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80w90 gives some better shock load protection and really heavy use load protection but it doesn't flow very well. In our climate it's perfectly acceptable to use it. If you're in the salt belt and northward it won't flow when cold. Not a huge issue as there is no pump in the front axle or in the the two bevel gear cases. The only issue is when you go to fill the axle housing and gear cases with 80w90 that is cold. It will take FOREVER to get it to flow into the gear cases and I mean forever. You'll be far better off changing it when it's warm outside and even then I like to stick the quart bottles of oil in the microwave for a min or two to warm them up, then dump em in. I purposely overfill the axle (to the top of the fill hole) then let them sit a day or two to settle into everything. At that point when you loosen the check plug, let it run out into a bucket until it's done running out, put the plugs back in and u r done.

or put super udt in it and let it ride.

I "like" 80w90 because it leaks out slower than super udt when (if) a seal begins to leak.

on a lot of the standard L series, during setup the front axle right side hub assembly is shipped OFF Of the front axle. So when the dealer tech is doing setup, he's got to take a plug off of the right side of the axle and then wrestle that 50+ lb hub assembly onto/into the axle. The whole time, oil usually leaks out. It's a pain, and messy. BUT if he's got it figured out, in other words knows how to lift and support the tractor so that all the oil runs to the other side, he will lose no oil and will be able to add a little before putting the hub in, and when done properly the axle oil level will end up PERFECT. Done it many times.

Secondly Kubota sends them (most all tractors) a little low on engine oil. Never seen one that wasn't. The M series 70+hp were always a quart or so low and the salesman hated the fact that there was always a $5 quart of oil added to the setup cost. Nothing I could do about it other than send it out a quart low which is not good. Hydraulic is "usually" ok, unless a loader is installed, then they're a gallon low, give or take. Axles are always low, standard L's always a couple quarts low. Coolant is usually close. So what generally happened over time was that there is VERY little leeway in the amount of time given to the setup tech, the new owner always wants it yesterday, the salesman is on the tech to hurry up, and stuff gets missed....like not checking the fluids after setup is "done". I don't miss it.
 
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Michigankubota

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B2650 Loader, Land Pride 64”Blower ,60”MMM , Land Pride 60”Box Blade.
Oct 17, 2018
229
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Bessemer, Western U.P.
I do not use any synthetic lubricants of any sort. It is my opinion that they are a waste of money. This reply is sure to get a lot of people to chime in and "correct" my thought process. I have been using the same old petroleum products for more than 50 years and never had a problem.
If you have a Kubota, you are using Synthetic oils. The UDT is Synthetic.🤓
 

Michigankubota

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B2650 Loader, Land Pride 64”Blower ,60”MMM , Land Pride 60”Box Blade.
Oct 17, 2018
229
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Bessemer, Western U.P.
When I did the 50 hour service on my B2650 I switched to a synthetic 75-90w in the front as my 2016 BX developed front axle pivot leaks at 160 hours with the Super UDT.
Messicks posted a video on YouTube that they switch all tractors out with gear oil when they come in for service.
 

GeoHorn

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May 18, 2018
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This is an excellent article on synthetic oil that is written from both sides of the fence - no mumbo-jumbo..... just simple facts for the layman.

https://www.machinerylubrication.com/synthetic-oil-31800#:~:text=Under a microscope, a drop,different shapes, sizes and structures.
That is an excellent description of the matter...with a small (perhaps insignificant) error or two.
The opening statement is easy to misinterpret...but in plain English it says that “synthetic” oils are made from “petroleum” oils. So...in actuality... it may be better to think of “synthetics” more accurately as “more highly-refined” petroleum oil.
The advantage of that process is fewer “stray” molecules in your oil such as wax/paraffin, volatiles, and sludge-producing errata.
The misunderstood part is that “sludge” “varnish” etc are not as harmful as people think. Pistons, rings, bearings, etc which slide against each other (protected by a film of oil) actually KEEP sludge/varnish (IF it develops at all) from accumulating in places that might be harmful. Where the varnish/sludge does accumulate is along block sidewalls, valve-covers, sumps, etc. where it does not interfere at all with engine operation and where in-fact it actually PROTECTS AGAINST rust/corrosion because it forms a barrier to the water-vapor your engine produces. (Want to give your engine a good shot of dirt and filthy circulating junk?... it’s easy...use one of the snake-oils and “cleaners” that are sold aftermarket that your vehicle mfr’r actually never authorizes....and you can send all that crud circulating thru your otherwise fine-running parts.)

When fossil fuel is burned the primary by-products (besides heat) are carbon monoxide, carbon dioxide, and water-vapor. The first two and most of the water is expelled thru the exhaust, but some of those things get down into the crankcase where they mix with the oil. The water-vapor reacts with that oil to create the sludge/varnish but also to react with sulfur and other items to create an acid. One of the additives commonly used in lubricating oils is designed to counteract that acid.... But acid still exists and so does the water-vapor and that combination produces rust and corrosion which deteriorates engine parts.
While a good filter will keep most physical-particle by-products from harming the moving parts, the acidic-solution continues it’s work inside the engine.
What helps fight that problem? FREQUENT OIL CHANGES! Which is why non-synthetic oils and their more frequent change-routines do almost the same good work as synthetics... but for a LOT less money.
I don’t use synthetics except where mandated by my vehicle mfr’s. (My Ram P/U requires it in the differentials. My wife’s Toyota Sienna requires it everywhere. But my boat, my tractors, airplanes, construction equipment, mowers, etc do not and they all get ”mineral” oil.... standard petroleum products. My Jeep has over 330K miles on the cheapest mineral oil I could buy... WalMart’s SuperTech SAE30 motor oil, and the $2 SuperTech oil filters. Did SuperTech get that vehicle to 330K miles...?? I can’t say that. But what I CAN SAY is that cheap SuperTech did not PREVENT the jeep from getting that far!
I’m not one who trades cars every 3-5 years. I keep vehicles until I wear them out or wreck them, and I have not had ANY failures from plain ordinary mineral oil and frequent changes of lubes and filters. Even cheap lube and cheap filters. (Air filters are probably more important than any other.)
The math in the article is suspect, but otherwise a good explanation. Thanks for posting it.

BTW, the concern over 80W90 gear oil in cold weather is largely unfounded. In gear-cases where roller-bearings, hypoid and straight-cut gears exist (like front axles) the 80W90 oil is not underperforming compared to synthetic light-weights like UDT/SUDT. The sliding nature of those parts immediately shear the gear oil and it rapidly performs it’s work of preventing metal-to-metal contact. Differentials of older equipment in arctic conditions never suffer from the kinds of imagined failures discussed so far. In fact, before 1990 differential oils were almost never changed in the lifetimes of pre-90 vehicles because the engines wore out sooner. It was only after the introduction of “synthetic” gear oils that OEMs began to require 30K-mile differential gear oil changes. Think about that.
 
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85Hokie

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BX-25D w/ Filled Rears,2" Spacers,PTB. Under Armor, 90'-90'-92'-B7100HST's
Jul 13, 2013
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Bedford - VA
Super UDT is synthetic. Look at the jug.

Not getting into a "pissing" contest....
but UDT - is just good ol fashion UDT - non synthetic
UDT2 was a blended oil - semi synthetic
S-UDT2 (Premium for the boys and girls up north) is synthetic......

ALl is forward and backward compatible.....mixing is OK ......
 
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