I thought the J20C was the low viscosity.
I thought the J20C was the low viscosity.
Just priced 5 gal bucket of low-vis hy-guard at my deere dealer just last week..... $81.42
76/conoco brand makes a low-vis trac/hyd oil meeting jd20D. Distributor did not have any or could give me a price. Had chevron synthetic THF that met jd20D for $110.00 for five gallon....
Amsoil's full-synthetic tractor/hydraulic stuff also meets JD20D, Prolly more than the chevron fluid in price though. They claim there syn tractor/hyd fluid is a 5-20 weight IIRC
I give considerable thought about just using "regular" tractor/hydro fluid... but I do use the 790 in less than 32 degree weather and low-vis fluid is what is recommended for use in the 790.
I'm just gunna buy low-vis hy-guard from the deere dealer. I need to change the stuff in mt 790 and check intake/exhaust engine valves, the 500 hour stuffs.
low viscosity hy-gard is an iso 32 lubricant. standard hy-gard and most other hydraulic oils are iso 46 or heavier. along with being suitable for hydraulic / hydrostatic applications, it is also suitable for gear transmissions. earlier this year i was trying to find mobil dte light which is the recommended oil for the gearbox in my lathe. it wasn't something i could find locally, so i checked to see what its properties were. turns out that it is an iso 32 hydraulic oil suitable for gear transmissions. i ended up using low-vis hy-gard in my lathe. i suspect that mobil dte light would be a suitable replacement for low-vis hy-gard, but it's harder to find and usually more expensive. when i bought the jd oil a month or so ago it was $18/gal, $85/pail.
It does make sence that an iso 32 hyd. oil SHOULD work in a hydrostatic drive system but, a 1023e has just a little more than just a hydrostatic drive system to operate with one oil.....
Large tracked and other hydrostactic driven machines that use iso 32 hyd. fluid in them often have large hydraulic driven motors that power a seperate final drive of some sort that is a totally seperate unit itself that takes a gear type oil in the final.
Depending on the year in IH 1480/1680 combine finals used "hy-tran" IH's tractor hyd fluid or 80w-90 gear oil. I know first hand that the finals that ran in the gear oil had considerable LESS gear/bearing wear as compaired to the finals that used the THF, with same amount of hours.
ISO 32 fluid may be fine for gear transmissions of a light duty or just a plain hydraulic system.... I would have serious reservations about using it as a tractor/hyd. fluid
An oils wieght rating iso 32, iso 46, iso 68, 5w-20 and such has little to do with the additives that make the oil what it is intended for.
i don't know how long the low viscosity hy-gard has been out, but my 770 is a 1998 model and it specified it then. i would assume that the entire production line of that tractor did too, so that dates it at least a few years before. you would think that by now there would be an equivalent aftermarket solution, because so many smaller jd models use it now. it would seem that there is a market for it since most aftermarket hydraulic oil brands are $30+ a gallon cheaper. unless it is like kfc original recipe and the secret ingredients are a well guarded item, i can't imagine there not being an aftermarket equivalent. that's kind of why i suspect that some of these other oils are equals.
if you look at what the oil is:
1: it is a cold weather replacement for original hy-gard.
2: it is an oil suitable for hydraulic systems, hydrostatic drives, and gear transmissions.
3. there isn't much of a cost difference between regular and low viscosity.
i think that if you have an iso 32 oil suited for hydraulic/hydrostatic/gear applications, then i'd bet it is compatible. for my time and money, i have always ended up buying the actual jd oil though. it's not like i change it that frequently, and when i need it, i usually have to go get filters at the dealer anyways. it's as close as any auto parts store is, and the local auto parts places aren't going to have all the filters or the oil need in stock anyways. for me it's just easier to make one trip and get what i need rather than chance the auto parts place getting a wrong filter and halting the process by another few days.
I'll probably end up going the JD route, too. Dealer priced j20c at $94/bucket, j20d at $85. Tractor supply has mid vis j20c equivalent at $35/bucket. No j20d.
According to my manual, I can use either J20 C or D in the tractor. They just shouldn't be mixed. There are plenty of cheaper alternatives for the J20 C out there.
Two questions, though:
1. Does anyone have a cheaper alternative to the transmission filter (OEM parts number LVA16054);
2. Does anyone have a parts number for the transmission suction screen? I'd like to pick one up for the next fluid change. That way I can just replace the used one with the new one and clean the used one and let it dry out real good.