Low Viscosity vs Hygard

bigtiller · Feb 9, 2014

Whats the difference? Why does my JD 2720 manual warn me not to mix them? Is it just viscosity or is there a chemical difference that turns to acid and blows up when mixed?

I will be changing the fluid and filter for the first time soon and the dealer strongly suggested I put in low viscosity hygard rather than the hygard the factory put in.

Do I need to purge the lines on my loader and snow blower?

BuilderML · Feb 10, 2014

I would say you are fine with Hygard, unless you are operating in sub zero temps all the time. With that being said in my unit Yanmar says to use J20C. Why in the same tractors they would call for different fluids is beyond me. I would stick with the Hygard if i was you. By the way the HYD. filter is a dealer only item but all other filter are available at Napa. Also if thats the original Hyd. filter on the unit it has 4 magnets inside the filter. Just clean them off and place in the new filter. Hope this helps.:drink:

DFB · Feb 10, 2014

Interesting...the manual for my John Deere 4100 (100% Yanmar built) says that you CAN mix the two and only warns against mixing with any "other" brands, BIO HY-GARD or using ATF. You need is to consider the ambient air temperature you will encounter again according to my manual reg. HY-GARD is shown rated for use down to about +15F where the LOW-VIS chart shows its acceptable down to around -20F. I haven't plowed in temperatures much higher than +10F the last several times I've gone out this year. For me I wouldn't worry about the small amount left in the system if you switch but it's up to you what your comfortable doing.

bigtiller · Feb 10, 2014

BuilderML said:
I would say you are fine with Hygard, unless you are operating in sub zero temps all the time. With that being said in my unit Yanmar says to use J20C. Why in the same tractors they would call for different fluids is beyond me. I would stick with the Hygard if i was you. By the way the HYD. filter is a dealer only item but all other filter are available at Napa. Also if thats the original Hyd. filter on the unit it has 4 magnets inside the filter. Just clean them off and place in the new filter. Hope this helps.:drink:

There are magnets in the filter also?

I have never done this but I have read here and in the manual, to look for magnets in the suction screen.

Industrial Toys · Feb 10, 2014

Very, very annoying! You never know what is simply protectionist behavior or a real harmfull possibility.

My Steiner says to use only Steiner Torque Fluid! How Stupid!

I use JD Low Viscosity in everything and I must revisit that because I was told that it may actually damage certain hydraulic wheel motors on machines that call for 10W30. Could this be true?

DeereMann · Feb 10, 2014

Well, this is interesting. My JD manuals have never mentioned not mixing HyGard & Lo Vis HyGard, including my latest tractor. In fact, my manual says Lo Vis is 'preferred' over regular vis. But the tractor must have been factory filled with regular vis (Georgia JD plant), because when I changed it @ 50 hour maintenance last year the transmission really quieted down.

Do you have something really unique on your tractor like a Limited Slip clutch pack or something?

I find Lo Vis performs better in all conditions - it flows faster in all hydraulic circuits. You just need to be sure to change it when you should, since it has viscosity index improvers that shear down over time (normal vis does not). This is no different than a multi-vis engine oil, in this respect. You won't get hydrostat transmission squalling & complaining when it's cold out, either.

Sure it costs more, but for changing only every 200 hours or so, it's not that big an expense.

You likely have metal debris magnets inside your suction tube screen. They aren't that strong, just shake the tube & they'll fall out. I wash off the metal debris from my suction screen in the drained hydraulic oil pan.

bigtiller · Feb 10, 2014

I'm going to use the low vis hygard and not worry about the little bit of hygard in the loader and snow blower plumbing. My manual has a different temperature chart than others have talked about.

OMLVU19798_F9

DeereMann · Feb 10, 2014

I think you'll be fine. You can always double check with a dealer as well.

BuilderML · Feb 10, 2014

bigtiller said:
There are magnets in the filter also?

I have never done this but I have read here and in the manual, to look for magnets in the suction screen.

Sorry i misspoke in my previous post my unit calls for J20A not J20C as earlier stated. Go figure same units and they call for different fluids. I think thats why these post can make ones head spin after awhile.:confused3:

I too had 4 magnets in the suction screen. Yes you should have 4 magnets in the hyd. filter they are the same type as the ones in the suctions screen. Its to easy to just take the filter off and put it aside and install the new one so look inside the old one first. If they don't have them inside it might not be a bad idea to add some as mine were dirty when i did my service. Can't hurt to pick up as many metal chips as you can. You'll need just under 5 gals. of fluid. My advice buy in 1 gal. jugs. it was a pain dealing with the 5 and putting into a smaller container to turn around and dump into he pin hole of a fill port. Have fun.