John Deere Hy-Gard in Manual Trans?

RiskyRick

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A number of people use it in autos in some really high hp apps with good results. Low on friction modifiers and deals well with gobs of heat. Comes in high and low viscosity.

Anyone have experience using it or equivalent fluids as a manual trans fluid, though?
 

UnleashedBeast

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I have zero experience or knowledge of this. However, after some investigation, I would not advise it.

John Deer HyGard

Viscosity @ 40°C................... 59 cSt
Viscosity @ 100°C................. 9.4 cSt
Viscosity index.................. 140
Pour point......................... -40°C
Flash point......................... 227°C

Viscosity index is low, therefore in cold weather, the lubricant will be very viscous. It won't shift very well until the transmission warms up. Viscosity @ 100*C is also higher than non-LV Amsoil ATF which is best suggested for Tremec. You can see how less viscous Amsoil is at cooler temps, with a higher VI.

Amsoil ATF

Viscosity @ 40°C................... 38.5 cSt
Viscosity @ 100°C................. 7.5 cSt
Viscosity index.................. 165
Pour point......................... -53°C
Flash point......................... 234°C

Same situation as Amsoil MTF Syncromesh. Even though the 100*C viscosity is close to John Deer, look at how much less it thickens as it cools (compare 40*C). VI is also far better. Best lubricant from Amsoil for the Getrag MT-82.


Amsoil MTF Synchromesh


Viscosity @ 40°C................... 48.3 cSt
Viscosity @ 100°C................. 9.7 cSt
Viscosity index.................. 190
Pour point......................... -46°C
Flash point......................... 218°C

Your street car transmission will shift far better hot or cold with either lubricant listed above, than the John Deer transmission fluid you are inquiring about. We also have no idea what additives are used in the lubricant. They may not work well with metal types used in your street car. It's best to stick with what's proven.
 
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RiskyRick

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I was asking because I've read where it was being used in some very serious race applications (mostly in powerglides), and I have easy access to it.

Isn't all that info pretty much consistent with the fact that you're comparing a dino oil to synthetic? Also, there are 2 weights- is that the low or regular viscosity? I'm no oil brainiac, but that low VI is saying that it's pretty low on index improvers correct?
 
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UnleashedBeast

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There are two ways to make an engine lubricant have a higher Viscosity Index. Using viscosity improving polymers which expand as the base oil is heated, or using a superior true synthetic base oil that naturally thickens less as it cools. I prefer a true synthetic base oil because viscosity improving polymers wear out rapidly, resulting in shearing (thinning to a lighter viscosity).

Now that you mention it, I did look again, finding a low viscosity Hy Gard formulation which is in the ISO 32 viscosity range (SAE 16 - lighter than SAE 20). No luck finding specifications on the lubricant for comparison sake. The version I compared above is normal viscosity. I'd assume they use the same base oil.

Other Google searches has confirmed there are people using it in their Power Glide, one guy killed it shortly after. Not blaming the lubricant, as the thread has no conclusion. Other people have used Amsoil ISO 46 compressor oil. Yeah, I was just as amazed as you probably are. People are using strange brews in their racing transmissions.
 
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RiskyRick

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There's no denying that a synthetic oil is more durable and has more consistent viscosity, but I don't think that takes away from dino oil unless you're in an app that has big temp swings (as in year-round use) or extended change intervals. Just because synthetic is superior doesn't mean that conventional is inadequate in every situation.

The tractor fluid is semi-popular on yellowbullet, but thats in race apps and it's being changed out often I'm sure. At the same time though, being low on VII's I would think that it would be fairly shear resistant.

Heck, theres people on there using Amsoil SCREW COMPRESSOR oil in their transmissions.

I'm really surprised that the amsoil syncromesh is similar in hot viscosity to the high vis- I did not remember synchromesh being that thick.
 

UnleashedBeast

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Sure, true synthetic is not required to race, and I'd agree with the lack of VII, the lubricant should have better shear stability. I was amazed as you were about compressor oil being used in their transmissions. Had someone ask me to buy him some on my Amsoil account for his race auto in a 2003 Cobra. My first thought was, "Wait, wut?"
 

KLeech

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I'll see what kind of info about the oil I can dig up as I work at a Deere dealership, I've tried to find some more in depth information before and came up empty handed. I'm not sure why they make it so hard to find the real info about it.
 

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