Step by step guide on how automotive gears work, article pertains to all vehicles.

Step 1 - Gears are use in many areas of a vehicle; in larger applications such the differential and transmission and for smaller applications such as a door lock or blend door actuator. All gears need to be lubricated to ensure proper operation.

Automotive Gear

Step 2 - Gears are made in one of two styles, helical and straight cut. These different types are used in various applications depending on operation and load. Helical cut gears tend to be used for heavy applications when a smooth operation is desired.

Helical and Straight Cut Gears

Step 3 - A gear can also be used as a sprocket which uses a chain or belt to drive an accessory.

Oil Pump Gear Sprocket

Helpful Information

A gear set allows the movement of rotational pieces from one axis to another. By turning gears which are connect it allows energy and movement to be transferred from one gear to another. Gears can also be used to help decrease or increase the speed of rotation by using gear ratios. For example, if one gear has 10 teeth and another gear which is connected has 40 teeth, the gear ratio is 4:1, the smaller gear turns 4 times to the larger gears once. This method also multiplies torque. Gears can be used as a method of changing shaft rotation through an even series of gears. This method will change a counter clockwise rotation into a clockwise rotation without any loss of power or rotation speed.


Written by
Co-Founder and CEO of
35 years in the automotive repair field, ASE Master Technician, Advanced Electrical and Mechanical Theory.


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