| A set of different size gears incorporated in one casting, used in a manual transmission. | |
| A transmission that changes forward gears automatically. | |
| Air injection reaction system | |
| In mechanical terms, wear of a component that exceeds designed limits; wear causes by overloading a part that is in an out-of-balance condition, resulting in lower-than-normal life expectancy of the part being subjected to the adverse operating condition. |