Generally speaking Gears operate in pairs to transmit and modify rotary motion and torque (turning force) without slip, the teeth of one gear engaging the teeth on a mating gear.  

Ring and pinion gears for the front and rear end of your vehicle come in a selection of gear ratios that vary how much torque is applied to the wheels of your vehicle. This ratio affects torque, gas mileage, and RPMs. Our engineer can design the pinion according to your required working condition.