I check it after every race day, ...as racing seems to be pretty hard on cars. I can't really describe how to do it, it's a feel ....you just kind of set it tight then loosen slightly ...i spin the wheels w/ my fingers to make sure there isn't too much resistance on the gears ...i am going for something that turns freely, yet not too loose not too tight. hard to describe, not sure there is a way to measure it. More of a feel.