GlossaryJan 15, 2026|1 min read

Backlash

The clearance between mating gear teeth and assembly tolerance.

Definition

Backlash describes the amount of clearance between mating gear teeth. This clearance is needed for thermal expansion and assembly tolerances.

Simple approach

Backlash = total clearance / number of teeth

Tips

Higher backlash can increase noise and vibration. Very low backlash can stress lubrication conditions.

Quickly validate backlash range.

Simple approach

Backlash = total clearance / number of teeth