Diagnostic Aids
WARNING: This page is about a different car, the 2003 Buick Regal, 2003 Buick Century, 2002 Buick Regal, and 2002 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
Inspect the flywheel ring gear for damage or unusual wear. Shim the starter as required. In order to add pinion to ring gear clearance a full size shim must be used. DO NOT shim only one starter mounting bolt. There are 3 shims available in different shapes, for clearance, all are 0.039" (1 mm) thick.