Diagnostic Aids
| • | 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 1 mm (0.039 in) thick. |
Step | Action | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |||||||
2 | Start the engine. Does the starter operate normally? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 | ||||||
3 | Start the engine while listening to the starter motor turn. Is there a loud whoop, it may sound like a siren if the engine is revved while the starter is engaged after the engine starts, but while the starter is still held in the engaged position? | Go to Step 6 | Go to Step 4 | ||||||
4 | Do you hear a rumble, a growl, or, in some cases, a knock as the starter is coasting down to a stop after starting the engine? | Go to Step 7 | Go to Step 5 | ||||||
5 |
Important: This is often diagnosed as a starter drive gear hang-in or a weak solenoid. When the engine is cranked, do you hear a high-pitched whine after the engine cranks and starts normally? | Go to Step 8 | Go to Step 7 | ||||||
6 | Inspect the flywheel ring gear for the following conditions:
Is the flywheel bent, or does it have damaged teeth? | Go to Step 9 | Go to Step 10 | ||||||
7 |
Does the clutch gear have chipped or milled teeth or worn bushings? | Go to Step 10 | Go to Step 9 | ||||||
8 | Shim the starter motor away from the flywheel by adding shims between the starter motor and the engine block one at a time. Flywheel runout may make this noise appear to be intermittent. Did you complete the repair? | Go to Step 11 | -- | ||||||
9 | Replace the flywheel. Refer to Engine Flywheel Replacement for the 3.5L (LZE) engine, Engine Flywheel Replacement for the 3.9L (LZ9) engine, or Engine Flywheel Replacement for the 5.3L (LS4) engine. Did you complete the replacement? | Go to Step 11 | -- | ||||||
10 | Replace the starter motor. Refer to Starter Motor Replacement . Did you complete the replacement? | Go to Step 11 | -- | ||||||
11 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
