Shift kit

A shift kit is a set of components for automobiles designed to improve how well the car shifts between gears. Kits are made for both automatic and manual transmissions.

Manual transmission kit
For manual transmission equipped cars, it is a component that replaces the stock gear selector (shifter). A shift kit usually shortens the throws of selecting a gear (also known as a short throw shift), therefore allowing a driver to reduce the shift timeand change gears more efficiently.

Automatic transmission kit
An automatic transmission's main focus is smooth shifting between gears. To accomplish this it often goes into two gears at once while shifting up, which is known as a shift overlap. In these cars, it is a kit that can reduce or eliminate the shift overlap.[2] It will also reduce wear because the transmission won't be trying to drive in two gears at once.

History
The term "Shift Kit" is a registered trademark of the company "TransGo" which originated the development of automatic transmission valve body improvement and upgrade components such as springs, valves, and instructional materials to improve the shift characteristics and durability of automatic transmissions.