I haven't been doing it for 20 years but I race alot and if you have the time to do it a little grease on the servo gears will make them last a little longer. I have wore some down to the point that there's slop in the gears. Better yet is to keep a check for any play and replace the gears if you get any play. Alot of racers don't keep servos long enough to see any wear.