Gear oil for Troy Bilt tiller
#1
Gear oil for Troy Bilt tiller
I recently was given a 1986 TroyBilt Pony rototiller. It is in need of oil for the transmission/PTO, and the manual says to use SAE 90 or SAE 140 oil only, and warns that use of multiweight oils could result in damage to the bronze gears. However, both SAE 90 and 140 aren't widely available anymore. Grainger carries it but they want $18/quart. Is there a more common subsitute that would be safe for my tiller? TIA
#4
Personally, I'd use regular 80-90 if it were mine. I have no idea how that oil could harm the gears. Oils are much more advanced and offer more protection than they used to. If it still concerns you, order the stuff from grainger.
#5
Thanks, I will use 80-90. I kind of thought the information in the manual was obsolete, I just wanted to make sure that I wasn't going to make a glaring mistake. They probably wouldn't pull SAE 90 and 140 off the market if their replacements weren't as good or better.
#6
After more research, I have found that some sulfur phosphorus additives in synthetic gear oils are corrosive to bronze gears, which explains the warning in the manual. I just have to look for 80w90 gear oil that is rated GL-4, which is designed to be safe for bronze gears.
#8
Tillers currently leave the factory with 75-140 synthetic GL5 rated oil. The caution about GL5 is for much higher operation temps and higher rpms in diesel engines, not a concern in the gear box of your tiller. The old GL4 spec is almost opsolete and notreadily available except in 55 gallon drums. Do NOT use a straight 90 weight as it will cost you new seals.