Gear oil for Hydro Gear?

Kevin Toadman

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Hello all, I have a mower with two EXT hydro units. I already changed the oil and went with the recommended 20-50 motor oil with success. I know if it ain't broke don't fix it but has anybody out there ever used a 75-90 gear oil in a hydro gear unit? Just curious, thanks.
 

mechanic mark

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You're quite welcome Kevin, let us know how it goes, thanks, Mark
 
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Rocky J

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I have not tried the 75/90 in the hydrogear but tried it it a wore out ford car engine and it foamed real bad . My Case loader uses hydraulic pumps and motor and it has stickers on it that warns to use only type F transmission fluid because the type A will compress and make the hydraulics spongy. So if you are looking for a experiment The Type F transmission fluid might stiffen up the response on the hydrogear. I also used the 20w/50 oil with no problems.
 

Kevin Toadman

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I have not tried the 75/90 in the hydrogear but tried it it a wore out ford car engine and it foamed real bad . My Case loader uses hydraulic pumps and motor and it has stickers on it that warns to use only type F transmission fluid because the type A will compress and make the hydraulics spongy. So if you are looking for a experiment The Type F transmission fluid might stiffen up the response on the hydrogear. I also used the 20w/50 oil with no problems.
Thanks for the info Rocky. I didn't think about the foaming. My hydro's are working fine, I just changed the oil because I got the mower from a friend and I know he never changed it, it's got a little over 300 hours on it. They came with 20-50 motor oil and that's what I went back with so they should be fine, I was just wondering if something thicker would make the units last longer. In GM hot rods we always used Ford type F fluid, the trans would take more abuse and slip less under load, it's good stuff, kinda hard to find these days though.
 

hlw49

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Just use what the manufactures recommend 75w90 is too thick and trans fluid is too thin. Lucas makes an additive for hydraulics. It is thicker and has a seal conditioner in it as well to help stop leaks. Follow the directions on the bottle if it that doesn't help much you can add more it won't really hurt anything and just could add more life to the hydro. Some of these older hydros are nla or really expensive.
 

Kevin Toadman

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Just use what the manufactures recommend 75w90 is too thick and trans fluid is too thin. Lucas makes an additive for hydraulics. It is thicker and has a seal conditioner in it as well to help stop leaks. Follow the directions on the bottle if it that doesn't help much you can add more it won't really hurt anything and just could add more life to the hydro. Some of these older hydros are nla or really expensive.
Thanks. I'll stick with the Castrol 20-50 oil. I did put a bit of Lucas oil additive also.
 

ILENGINE

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Hydrogear uses 20W50 at the factory, but I have seen 5w30 10w30 10w40 15w40 and 20w20 all used by various manufacturers in Hydrogear units.
 

Kevin Toadman

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Thanks, wow. I'll stay with 20-50 since I'm in Texas and never run them in the winter.
 
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