When you have a complete board setup, you can be ignore mainanance and probably be fine untill something shows obvious signs of being a issue. However, if you want to keep your setup in the best shape these are what I take care of.
The metal of precision trucks should last pretty much forever. Unless something got bent or F'd in another way.
Decks can last a couple of years before you notice any degradation. Carbon fiber decks pretty much never warp. The wood in any deck as well as the lamination can break down a little, but unless you are rainskating all the time its eh.
Truck axle and kingpin nuts should be replaced before they go bad, about every year or two. Pivot cups should be replaced a little sooner than that.
Bushings could use replacing about every year. Bearings last around that long as well maybe a little less.
Unlike street skating, grip tape on a downhill board doesn’t last the life of the deck. Since decks last super long and the grip tape wears faster, you might need to re-grip about every six months if you skate often.
Wheels need to be replaced when you core them or mess them up.
