Horse Mower Gear Oil

[daynee]

I have a horse mower, which is in need of an oil change. I seen on my last post it says to put 20 S.A.E in the case or 10w foam depressed hoist oil, which I have learned those two oils are very hard to find. What would work the same as those oils in the mower gear casing?

thanks

dayne
 

[RN]

Some of the old small engines with splash lube called for straight non detergent 20 weight winter use and the more recent advisery is use 10-30. Couple cars also say use 10-30 engine oil in transmissions for winter- I had a 1980s Sunbird that would have almost locked tranny with regular gear oil in winter and then read the manual on the suggested oil. Japanese motor cycles with common oil in engine and transmission say use the 10-30, 10-40 as the thickening additive is a good gear lube. SO, a couple of gear lube requireing applications are saying the multiviscosity engine oils are acceptable- and a Walmart gallon of 10-30 is about $5.99. Only consideration I"d be concerned about is possible brass gears and seals leaking- and the minimal sulpfur but higher zinc "high mileage/older car formulas" or Diesel spec have the zinc in them yet that acts as a "pressure/wiping" lube that is needed for gears and plain bearings. The old low speed gears calling for 20 weight mineral oil seem to be addressed by use of the more available 10-30. 20 weight hydraulic oil as you noted is getting hard to find on common store shelves. Type F tranny fluid is the other gear lube suggested for some transmissions- this was the old Ford standard until 1970s/1980s and is slightly lighter than the Dextron- it advantage is doesn"t carry fine chips and grit, allows the crud to fall to bottom of oil pan and has a harder grip on some friction material to metal while still having pressure/wiping capabilities. Old Harley transmissions used in winter for sidecars- parking and traffic police use- in Milwaukee and other northern city/states had this advisory for the dealers. Dextron is advised for some trannies and rear ends- alternative winter use, Alaska use and a few small equipment -like snowblowers gear drive- uses. I use the 10-30 in tiller, small motorcycle general use and 15-40 Diesel spec in some other warm weather use. RN
 

[James Howell]

The SAE 20 is available at Tractor Supply.