I think the new manuals say to change the engine oil and the hyd filters @ 50hrs. I believe the 50hr change is one of the most important. It seems that most owners only change the engine oil / filter and the hyd filters, myself I have done a full service on every new tractor I've bought. On each one the hyd oil has been full of fine metal shavings. And the oil in the front axle is almost scarry at the ammount of metal in it.