I had my antifreeze flushed and changed to long life antifreeze at about 500 hrs when it was eight years old. It uses the same antifreeze as the Cat C7. Did not change the belts, but I have spares with me. Haven't thought about the thermostat. Filters get changed once or twice a year. Depends on usage and if I'm near a shop I like. Onan 7500.
Bill
Nodwell RN110 out moose hunting. 4-53 Detroit, Clark 5 spd, 40" wide tracks, 10:00x20 tires, 16,000# capacity, 22,000# weight. You know the mud is getting deep when it's coming in the doors.