trans oil and low usage

[jima1]

What's the conventional wisdom on the need to change transmission oil in low-usage situations?

My tractor gets less than 50 hrs/year, but the transmission oil is 2 years old. The manual recommends trans filter change every 200 hrs, trans oil change every 300 hrs., so with more typical usage I'd be changing something soon. I'd never let the engine oil get old, but am wondering if there is harm to let the hydraulic oil go for a few years? Just change the filter sooner?

I'd like to understand if there is a real danger here (as with engine oil), not just change it out of suspicion. Didn't see a recent discussion or find one in a search, let me know if it's already been covered somewhere.

Thanks,
Jim

 

[BobinCols]

50 hours is not much use in a season as you stated. I would change the engine oil and filter every year. If it was a gear trans I would stick with the manufacturers hourly recommendation you stated. If it was a HST trans, I would cut the hours down on filter replacement to 150 and the fluid and filter replacement to 250.. For added protection either way I would use a synthetic gear oil when changing but not necessary.

 

[jima1]

Yes it's an HST trans.

Is the main concern to keep the hyrdraulic fluid clean or would there be some other issue with older oil?

 

[BobinCols]

Yes, you want to keep the hst hydraulic oil clean. A hst trans runs hotter and has valves and clutch packs (than a gear trans). Loader work is a lot harder on a trans than mowing your yard. If all your doing is mowing, you can probably get by with the manufacturer's maintenance schedule.

 

[Chillimau]

I have the same situation with low hours. I asked the same question about changing the transmission oil and was told that sometimes moisture can be a problem. As the temperature changes, air moves in and out of the transmission and you get condensation in the transmission.

Anybody experienced this?

Gary