A finishing process for spiral bevel and hypoid gears in which the hardened pinion and gear are run together under light load with an abrasive slurry while the machine varies their relative position. It smooths the surfaces, refines the contact pattern and reduces noise. Lapped gears become a matched set, marked with a serial number and often a mounting distance, and must be replaced as a pair.
Ring and pinion are a lapped set, check that the etched numbers match before you install them.
Also heard as
- gear lapping
- lapped set
Related terms
Spiral bevel gear
A bevel gear with curved, oblique teeth that overlap in engagement for smoother, quieter right-angle drives.
Hunting tooth
A tooth combination with no common factor, so every pinion tooth eventually meets every gear tooth.
Contact pattern
The imprint left on gear teeth by marking compound after running, showing where and how the teeth touch.
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.