What weight oil to use in bush hog gearbox

My nephew borrowed my brush hog and noticed the gear oil was a bit low. He put in SUDT2 instead of 90 gear oil. He said it was not much, a few ounces, maybe a cup. I don't see any way to change it except maybe vacuum it out. Will that bit hurt a gear box, it is not used that much but I don't want to screw it up.

I don’t think it will hurt anything other than being to light. I would get s suction gun and remove the oil and replace with 90w. It needs it anyway. Look over the bottom seal or pinion seal to see if you can find a leak. Catch and repair early before you burn it up. At least he checked the gearbox, praise him for that

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I dont think it will hurt a thing.. I only worry if they go dry or if there is water mixed in.

If it hasnt been changed ever, maybe when you get it warmed up, use your extractor to suck the quart or two out and give it a fresh dose of your favorite gear oil..just my opinion.

Thanks, I will change it before I use it again. Just got through plowing snow so it will be a while before I hook the mower up. I didn't know if the Super would enhance the fluids in the gear box, lol. He only used it about an hour so probably did not get it too hot.

Thanks, I will change it before I use it again. Just got through plowing snow so it will be a while before I hook the mower up. I didn't know if the Super would enhance the fluids in the gear box, lol. He only used it about an hour so probably did not get it too hot.

Typically, Bush Hog wants a gear oil containing an Extreme Pressure Additive.
From their web site:
Multi-Purpose Gear Oil EP80W-90

The EP standing for Extreme Pressure.

Dave

OK all ya'll that are much smarter than I, got a question relating to this.

Good question by the OP. We use large syringes here at work so I got a couple of used ones placed a piece of 5/16" tube on it and sucked the oil out of my hog gear box and refilled.

Question, Kubota says I can use SUDT2 in the front end of my L4600 replacing the gear oil that came in it.

So, if Kubota says the SUDT2 oil can be used in place of the gear oil, is it possible the hog in question would be ok or even better if the SUDT2 was used?

Just curious what your thoughts are.

Jay

Some people use the term "gear oil" without actually realizing other people think 80w90 when they hear that term.
SUDT2 ... IS... a type of gear-oil. It's just not likely specified by anyone for any product other than Kubota equipment.
And mixing the two different oils was doubtless not a good idea. Different fluids are almost always not to be mixed.

MY Kubota actually says the OPPOSITE. They allow the original Kubota UDT in the front axle to be replaced with 80W90...

by the owner.

I think that just adds to the confusion of matters. Kubota should be more explanatory, IMO, as to why they allow 80W90 in the front axle equally rated with UDT or UDT2, for that purpose etc. I suspect it's because the front axle fluid isn't used for hydraulic purposes...only gear/bearing lubrication.

Are you sure you didn't get the instructions backwards yourself?

I'm surprised the gear box didn't have the specified fluid labelled on the unit.

(And while your nephew probably thought he was doing you a favor, the question I'd ask him is, "Why did you not call me first before you decided to do something to my equipt? Would you like me to do that to you? Do you now see why maintenance manuals and specifications are produced?"

My nephew borrowed my brush hog and noticed the gear oil was a bit low. He put in SUDT2 instead of 90 gear oil. He said it was not much, a few ounces, maybe a cup. I don't see any way to change it except maybe vacuum it out. Will that bit hurt a gear box, it is not used that much but I don't want to screw it up.

Won't hurt anything.

Do not overfill.

SDT

if you live in a hot climate run the gear oil, if you live where it is colder and use it in the winter use the super UDT2 Kubota Super UDT2 provides the following benefits to Kubota equipment:
Improved transmission performance and protection at high and low
operating temperatures
Unique friction characteristics on wet clutches enables smoother start off, drive control, and PTO connection
Fully interchangeable with standard UDT and Super UDT fluids
Superior corrosion resistance and efficient filterability protects transmission
and hydraulic systems
Improved transmission efficiency through reduction in power loss
Meets Kubota stringent specifications
BOTH ARE HYDRAUKIC OIL, THE UDT and SUDT2 ARE THINNER WEIGHTS