I grease my tractor and the deck when I put it on. The mower runs for about 1 hour every two weeks. It might see 12 to 15 hours of use all summer, same with the tractor. Tractor runs longer than than, maybe 1.5 hours per mow. So if I never take the deck off or use it the tractor for anything else I grease everything up again when I take the deck off for the winter. If I use the tractor for something else I generally take the deck of and put the FEL back on. In this case I grease everything back up when I put the deck back on. So you might say I sorta follow the recommendation of every 10 hours of use, more or less.