Factorial experiments are difficult to apply to gear noise development due to the large number of variables and interactions that affect gear noise. A test procedure has been developed which takes into account that gear tooth lead is one of the most significant factors. This procedure establishes a lead target before running a factorial experiment by doing a lead study ahead of time. This has two advantages: 1.It will amplify the effect of the remaining factors in the experiment. 2.It will provide better targets for manufacturing.