The starter motor on your Chevrolet engine is designed to spin when you turn on the key, which spins the flywheel and starts up the engine. The relationship between the flywheel and the starter gear can be a bit finicky, and if there isn’t enough clearance between the two gears, you can get grinding sounds, and have problems starting. The fix is to add a starter shim or two, depending on the proper spacing.
Lift up the front of the vehicle using the jack and secure it on jack stands. The vehicle should be completely secure on the jack stands before you crawl underneath it.
Disconnect the positive terminal of the battery using an open-end wrench. Crawl underneath the vehicle and locate the starter, which will be near the flywheel between the transmission and the engine.