Hydro tranny maintenance question

[Boogity 0]

I've been running my 3415H for a long time (8 years or so) without any need to service my hydro drive. The fluid is always full and fairly clean and I never have any problems with it. But I'm getting more concerned avery year. I do not have any instructions on maintenance. Can you guys make any recommendations? Usually "if it ain't broke, don't fix it" is good advice - but I'm sure there is some kind of preventative maintenance I should be doing.

[D-17_Dave 12]

Once a year is the average I normally go by unless the tractor sees comertial use.

[Roy 0]

I think the Service Manual for my newer Sovereign recommends a fluid and filter change every 400 hours. You can download a manual for your tractor from Simplicity Publications to find info on your tractor.