A design choice in which the tooth counts of a pair share no common factor, such as 41 and 11, so each pinion tooth meshes with every gear tooth before the pattern repeats. Wear and minor tooth errors spread evenly instead of mating the same pairs over and over. Non-hunting ratios, such as 39 and 13, repeat contact between the same teeth and must be assembled with timing marks lined up after lapping.
It's a hunting tooth ratio, so no timing marks to worry about, just set the lash and the pattern.
On a lapped non-hunting set the marked teeth must mesh again at assembly, or the lapping was wasted.
Also heard as
- hunting ratio
- hunting tooth ratio
Related terms
Gear ratio
The number of teeth on the driven gear divided by those on the driver, setting speed reduction and torque gain.
Lapping
Running a matched bevel or hypoid pair together with abrasive compound after heat treat to refine contact.
Ring and pinion
Shop name for the hypoid final drive in a vehicle axle, named by its ratio, such as 3.73 or 4.10.
Bull gear
Shop name for the biggest gear in a drive train, usually the slow, heavy output gear.