Thrust Washer Inspection
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, 2003 Chevrolet Cab & Chassis Silverado, and 2002 GMC Sierra. However, it is still accessible from the selected car via links, so may be relevant.
Measure thickness of thrust washer at several places around washer. Compare measurement to specifications. See FRONT SUPPORT & MAIN PUMP MODULE SPECIFICATIONS table under TRANSMISSION SPECIFICATIONS. If minimum thickness is not within specified limit, replace thrust washer.