Traditionally, gear rating procedures on directly consider manufacturing accuracy in the application of the
dynamic factor, but only indirectly through the load distribution consider such errors in the calculation of
stresses used in the durability and gear strength equations. This paper discusses how accuracy affects the
calculation of stresses and then uses both statistical design of experiments and Monte Carlo simulation
techniquestoquantifytheeffectsofdifferentmanufacturing and assemblyerrorson rootand contactstresses.
Manufacturing deviations to be considered include profile and lead slopes and curvatures as well as
misalignment. The effects of spacing errors, runout and center distance variation will also be discussed.