Buying Advice Chance to buy L4400 HST

[rScotty]

It came to pass when I used Deere trans fluid (had it on hand) in my B7800 that has a hydro. The difference was immediate in that I had more whine and it didn't have the tightness and responsiveness it had before. If I recall, it was not many hours before I dumped it and went to SUDT2. I did a thread on it. It's interesting about the NH G134 and I don't know why that would be different than the Deere. I know I used it in my 2110 and 1900 Ford gear drives and I liked it.

I just researched it a bit and learned there is a NH134 and a NH134B but I have no clue about that. I'm all ears on this and interested to know anything you might know. Trans fluid is like a dark art but I suspect synthetics are the wave of the future.

Six Dogs, sure you hit it on the head when you calls trans fluid a dark art. I also suspect that synthetics are the wave of the future simply because traditional refining has become so complicated when it starts with an incoming crude base sourced largely by price. Synthetics are building the oil molecule up, instead of refining it down, so they don't have that same sourcing problem. Their problem is the cost of synthesis. I agree that synthetics are the future.

I DID ask the Kubota dealer why he used New Holland/Ambra Multi G134 instead of Kubota's own trans/hydraulic fluid & half expected some song and dance. But he simply said that being just down the road from a NH dealer that serviced a lot of big Ag equipment, he could buy their NH MultiG product in greater bulk and at a better price than the Kubota UDT . He had never noticed any difference that he could attribute to the different fluids. Simple as that. He seemed surprised that I noticed any difference in the HST sound.

Trans/hydraulic fluid is even a darker art than engine oil, since trans/hyd oil is a single oil but having two different and conflicting sets of requirements. The "trans" part has to have a lot of shear strength and desire to cling to surfaces in spite of efforts to move it away, while the "hyd" part has to flow past those surfaces and through small orfices as easily as possible. And then the resulting trans/hydraulic fluid has to be compatible with seals, in spite of the fact that the fluid is chemically very close to being a solvent for those seals. It has to penetrate enough to keep seals supple and then lubricate the seal lip without dissolving the seal or leaking past.

I've been fascinated by oils and particularly transmission & hydraulic oils & their chemistry for a long time. But in spite of 50 years as a mechanic, machinist, & mechanical engineer I don't really know much about them. It's not been for lack of effort. I've researched, read, poked at seals and blotter samples for half a century now.... and I still have to say that what I know is limited to bias and opinion. I wish there was more science. behind my opinions, but honestly most of it is simply what I've observed. The internet info I've found on the subject seems mostly opinion as well.

So how do I choose a trans/hydraulic fluid? Well, I am influenced by sound most of all. The quieter the better. I've no idea why one would sound different from another. But sometimes they do.
All the oils seem to do a surprisingly good job taking care of seals. I can't say that about fuels. And yes, I'm old fashioned enough that I like for an oil to "feel" oily between my fingers. I sometimes change filters and keep the same oil.
rScotty

 

[Herkypilot]

To the OP,
I settled on two tractors also, an L3540 HST that I bought used to take care of the small chores and a larger M7060 cab for Bush hogging and larger stuff. I end up using the L3540 quite a bit more than the M7060, but it has it's place. I think it's too much of a compromise to make one size tractor do all if you have a wide variance of jobs to do. If you buy one, it will never be quite right if you have a hobby farm.

HP

 

[sixdogs]

rScotty--it sure seems the manufacturers have deliberately made things confusing, probably so they can make it appear that their product is proprietary and special. I've gone through lots of trials with trans fluid and have learned that gear drives do well with anything that meets specs. It's hydros that are fussy and I think the problem is guys put in oil too thick for the application. They use regular store branded trans oil in the winter and I thnk that's a thicker viscosity than most hydros prefer--and OEM's use.

I think that's why Deere has reg trans HyGard and then low viscosity HyGard for winter. Now, I have used this "low vis" HyGard in a hdro in cooler weather and the transmission acted just fine. It didn't act right with thicker oil. That makes me believe there are two basic oils, regular and low viscosity. It could be that some or most OEM trans oil is really lo viscosity oil with additives that help it with gear drives and that store bought regular trans oil is thicker. I don't know.

Things have now changed because Kubota came out with the SUDT2 synthetic and that is wonderful all the time, hot or cold. My hydro Kubota loves it as does my hydro-shuttle so that's all that I use. Gear drives get regular dino trans oil and the hydro and shuttle get SUDT2 only.

I suspect things are about to improve and the world may beat a path to our doors with synthetic trans oil. That will be wonderful from a simplicity standpoint and also lower prices from increased competition. In reality, probably the worst oil today is probably better than the best oil of 15 years ago. Oil makers have done a great job but I'm now ready for synthetic.



Now, stay with me for one other thing I wonder about. I read something a few years ago that just hit home. It was a conversation about gear oil or trans fluid in the front of FWA Kubota axles and one of the guys said that gear oil in the front axle built up higher pressures than trans oil. He explained that both oils lubricate about the same but he thought that's why Kubota ships with trans oil in the front axle and not gear oil. Since all of us rush to swap out that oil for gear oil, I wonder if the increased pressure from gear oil, if that's true, is behind some of the axle and hub seal leaks I see in posts on the TBN. Just a thought.

 

[rScotty]

Now, stay with me for one other thing I wonder about. I read something a few years ago that just hit home. It was a conversation about gear oil or trans fluid in the front of FWA Kubota axles and one of the guys said that gear oil in the front axle built up higher pressures than trans oil. He explained that both oils lubricate about the same but he thought that's why Kubota ships with trans oil in the front axle and not gear oil. Since all of us rush to swap out that oil for gear oil, I wonder if the increased pressure from gear oil, if that's true, is behind some of the axle and hub seal leaks I see in posts on the TBN. Just a thought.

Not sure I'm following this idea. Where would the extra pressure in the front axle be coming from? There's no pump in the front axle, just a stirring motion. And besides that, the front axle is vented to the air. I'd think that if there was any pressure it would simply vent away.

Now if you are talking about the face-to-face pressure of the gear teeth on each other as they contact each other, that will be different if using gear or hydraulic oil. But that's happening at the microscopic level as the teeth wipe past each other. Not the sort of thing we would see or even know about. Certainly I don't know much about it. But I don't see it putting pressure onto any of the seals.
So I don't see any pressure in the front axle regardless of type of oil.
rScotty

 

[sixdogs]

Not sure I'm following this idea. Where would the extra pressure in the front axle be coming from? There's no pump in the front axle, just a stirring motion. And besides that, the front axle is vented to the air. I'd think that if there was any pressure it would simply vent away.

Now if you are talking about the face-to-face pressure of the gear teeth on each other as they contact each other, that will be different if using gear or hydraulic oil. But that's happening at the microscopic level as the teeth wipe past each other. Not the sort of thing we would see or even know about. Certainly I don't know much about it. But I don't see it putting pressure onto any of the seals.
So I don't see any pressure in the front axle regardless of type of oil.
rScotty

I don't know but I would think the frothing action of one or the other creates some sort of pressure from the activity?

 

[Fallon]

I don't know but I would think the frothing action of one or the other creates some sort of pressure from the activity?

Frothing will only occur where air & liquid meet. So intrinsically that's going to only happen at the top. Air or aerated oil isnt going to settle down through denser oil through the steering components. Frothing isnt going to change the pressure more than thermal expansion will. Practically nothing for air pressure with a properly working vent. The weight of the oil would exert some pressure on seals, but that will always be the case.