Straight from Google:
Reverse gears are straight cut while forward gears are helical (a helix or spiral shape) because it creates a bigger contact area for the gears which creates higher torque.
You don’t need a lot of torque when reversing so the gear is cut straight creating less contact area which makes a different sound then the forward gears.
ElI5: Smooth gear makes different sound than a gear with grooves.
Latest Answers