Mower King
Well-Known Member
- Joined
- Sep 19, 2018
- Threads
- 20
- Messages
- 663
A high/good grade of 20-50 engine oil.....if you lift up the seat, there will be a sticker that says that.....if the sticker is still there!
WHAT BRAND OF OIL FOR THE HYDRO-GEARS IN AN "IS 700Z"
- Thread starter stealurfish22
- Start date
A 9.0 cst oil is a SAE20 to SAE30 at 100C temp.
20w-50 oil has a viscosity rating of 19 cst at 100C or 212F.
Two completely different grades of oil. Please pass the pipe around. That's some awfully thick hydraulic fluid at 20w-50.
Must be typical American over thinking things. Manufacturer calls for vanilla ice cream. American public chooses a banana float.
slomo
Did they say with a straight face that the "traditional" oil does not sheer down to something less than the required minimum 120 celsius viscosity over the 400 hour service interval?
Or deteriorate in other ways? Does anybody here believe that the traditional oils are "just as good" as the high end synthetics?
I could do an UOA at the end of 400 hours with a traditional hydro oil to prove this, but that means I would have to take a risk on the longevity of my hydros to prove this point.
It is not worth it to me. If I only expected to get 5-10 years out of my Hydros, maybe it would not matter. I would like to get 20 years, if I live that long.
It makes more sense to me to err by being extra cautious and use the synthetic recommended by the makers of my mower .
It is relatively little extra money over the life of the hydros, for my peace of mind.
ILENGINE, let me ask you this: Do you follow your own advice? What fluid do You run in your Hydros?
Or deteriorate in other ways? Does anybody here believe that the traditional oils are "just as good" as the high end synthetics?
I could do an UOA at the end of 400 hours with a traditional hydro oil to prove this, but that means I would have to take a risk on the longevity of my hydros to prove this point.
It is not worth it to me. If I only expected to get 5-10 years out of my Hydros, maybe it would not matter. I would like to get 20 years, if I live that long.
It makes more sense to me to err by being extra cautious and use the synthetic recommended by the makers of my mower .
It is relatively little extra money over the life of the hydros, for my peace of mind.
ILENGINE, let me ask you this: Do you follow your own advice? What fluid do You run in your Hydros?
Slomo, note that Hydrogear lists the cSt at 120 celsius. At 100, this would translate to a higher cSt, so
you cannot directly compare the @100 and @120 values. It is a high shear, high temperature application.
Hydros may run as high as 150 celsius, so the heavy, high viscosity 20w50 motor oil they call out is actually required.
Going to an even higher viscosity such as somethingw60 would sacrifice cooling efficiency.
They recommend motor oil instead of the even higher viscosity gear oil, because of the typically high temp environment.
(Gear oil could be something like 75w90)
you cannot directly compare the @100 and @120 values. It is a high shear, high temperature application.
Hydros may run as high as 150 celsius, so the heavy, high viscosity 20w50 motor oil they call out is actually required.
Going to an even higher viscosity such as somethingw60 would sacrifice cooling efficiency.
They recommend motor oil instead of the even higher viscosity gear oil, because of the typically high temp environment.
(Gear oil could be something like 75w90)
ILENGINE
Lawn Royalty
- Joined
- May 6, 2010
- Threads
- 44
- Messages
- 10,774
Hydrogear units get the Hydrogear branded 20w50 oil unless the mower manufacturer recommends something else. Some call for 10w30, some 10w40, some 20w20 hydraulic oil. Tufft-torg get the recommended 5w50 tuff-torq branded synthetic oil. A few even use their own branded oil with no cross reference like the oil recommended in some IH cub cadet transmissions. JD get the hy-gard Low vis for the unit that use that oil.Did they say with a straight face that the "traditional" oil does not sheer down to something less than the required minimum 120 celsius viscosity over the 400 hour service interval?
Or deteriorate in other ways? Does anybody here believe that the traditional oils are "just as good" as the high end synthetics?
I could do an UOA at the end of 400 hours with a traditional hydro oil to prove this, but that means I would have to take a risk on the longevity of my hydros to prove this point.
It is not worth it to me. If I only expected to get 5-10 years out of my Hydros, maybe it would not matter. I would like to get 20 years, if I live that long.
It makes more sense to me to err by being extra cautious and use the synthetic recommended by the makers of my mower .
It is relatively little extra money over the life of the hydros, for my peace of mind.
ILENGINE, let me ask you this: Do you follow your own advice? What fluid do You run in your Hydros?
Viscosity cst is rated at 100C or 212F. Hydrogear is confusing the situation by using some non-standard recommendation.
The original post said 110C and a 9.0 cst. Still an SAE20 to SAE30 oil.
So from what you said Hydrogear is saying, a 9.0 cst at 120C is perfect for an SAE30 oil.
An 80w-90 gear oil is roughly the same viscosity as SAE30 engine oil.
Engine oil cst ratings
GEAR or transmission oils
Notice they list cst at 100C.
slomo
Hydrogear doesn't make the SAE classifications. Don't care what they list. Why can't they list some cst at 100C like the SAE rating?
You are correct about the 120C and slightly higher cst. Still not a standard comparison to real cst values. Don't know about high sheer at all. Nothing is sheering. Just a pump that builds pressure that creates heat while doing. Shearing is when two gears mesh together smashing oil molecules breaking the oil down.
150C is roughly 300F. Time for an oil cooler. A 0w-20 can handle 150C all day long. So your "thinking" you need some roofing tar because it's at high normal operating temps is off.
slomo
