Define Gearbox

by Rick Carlton

A gearbox is a collection of mechanical components that deliver maximum power from an engine by managing a series of gear ratios that in turn operate a transmission. These components include: a gear selector, fork, collar, dog teeth and a gear set.

Gear Selector

This is a hand-operated device that allows a driver to choose a gear that creates a match between engine revolutions per minute (RPM) and a particular gear ratio


The fort is a connecting device that accepts forward and backward movement between the gear selector and the fork by use of a horizontal rod.


Also known as a "dog ring," the collar is a rotating component that slides across a horizontal shaft connected to the car's differential. The purpose of the collar is to positively engage a selected gear.

Dog Teeth

These are extruded features around the collar that create a connection between collar and gear by inserting them into holes around a gear. When the collar/gear combination is secured, the system creates power synchronization between the engine, transmission, differential and the final drive.

Gear Set

A gear set is a collection of rotating components that engage an engine/transmission combination to produce a desired RPM.

About the Author

Since 1984, Rick Carlton has authored more than 450 articles on the principles, application, analysis and deployment of interoperable enterprise technologies. Additionally, he has written more than 150 feature articles on aviation, auto and motorsports topics including work for The Auto Channel, "Automobile," "Flight Training" and "On-Track" magazine. He holds a Bachelor of Fine Arts in music from the University of Missouri at Kansas City.

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