[rotorwrench]

Straight cut gears don't have much for thrust loads like the helical gears do but wear on gear faces, shaft splines, and shifter fork slots can allow enough room for gear movement. The shifter detents are very important in these type transmissions to help hold the gear. The ball tip on the shift lever can also wear out. Too much play may not allow a gear to properly center on the other gear during shifting.