YM-240 Transmission/Hydraulic Fluid Recommendation?


New member
Curious to know what trans fluid is recommended and where the most economical place to get it might be? The manual calls for 4 gallons of John Deere 303 or "Hy-Grad" which seems to be a typo in the manual? I'm seeing "Hy-Gard" all over the internet but I read an article about the dangers of 303?:


I don't want to go so cheap as to cause any problems with components but don't feel I need top-of-the line stuff either. Are there other brands that meet specs you guys might recommend?

Thanks in advance!


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I run the '303' UTF from Tractor Supply or Autozone in my YM240, I figure it is as good as what Yanmar expected 40 years ago. It's single weight (viscosity) which is likely why the manual says 5 minute warmup before running - and in cold weather that is realistic advice. My use doesn't run the tractor long and hard at maximum output, if I did I might step up to better UTF. But I've never heard of a problem using this in a simple gear transmission.

On the other hand I buy Tractor Supply's premium UTF (Hy-Gard equivalent) for my other tractor which has Powershift, a transmission nearly identical to an automotive A/T but no torque converter at the input. Just a direct mechanical driveshaft going back from the clutch. That one relies on its internal clutch packs to get the tractor moving and complex hydraulic valves to control the shifts. It feels sensitive to oil viscosity. It likely benefits from fluid rated for minimal brake grabbing, wet clutch chatter etc and other characteristics of oil formulated for modern applications including hydrostatic transmissions.

Those two are the cheapest UTF's available. I think they're adequate for what Yanmar expected 40 years ago. For a YM240: 303 if your climate is moderate, Hy-Gard J20D equivalent if you plow snow etc. Maybe more expensive oils if you think the tractor will still be in service after another 40 years.