Gear Tooth Contact Pattern Inspection: Notes
WARNING: This page is about a different car, the 2003 GMC Safari, 2003 Chevrolet Astro, 2002 GMC Safari, and 2002 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.
The contact pattern check is not a substitute for adjusting the pinion depth ad backlash. Use this method in order to verify the correct running position of the ring gear and the drive pinion. Gear sets which are not positioned properly may be noisy and/or have a short life. A pattern check ensures the best contact between the ring gear and the drive pinion for low noise and long life.