See the Starter Motor Noise Diagnosis chart (Fig.
9). If the complaint is similar to Conditions 1 and 2 in the chart, correction can be made by placing shims between the starter motor and the engine block using the following procedures:
CONDITION |
POSSIBLE CAUS |
CORRECTION |
1. VERY HIGH FREQUENCY WHINE BEFORE ENGINE STARTS; ENGINE STARTS OK. | 1. Excessive distance between pinion gear and flywheel/drive plate gear. | 1. Move starter motor toward flywheel/drive plate by removing shim(s), if possible. |
2. VERY HIGH FREQUENCY WHINE AFTER ENGINE STARTS WITH IGNITION KEY RELEASED. ENGINE STARTS OK. | 2. Insufficient distance between starter motor pinion gear and flywheel/drive plate runout can cause noise to be intermittent. | 2. Shim starter motor away from flywheel/drive plate. Inspect flywheel/drive plate for damage; bent, unusual wear, and excessive runout. Replace flywheel/drive plate as necessary. |
3. A LOUD "WHOOP" AFTER ENGINE STARTS WHILE STARTER MOTOR IS ENGAGED. | 3. Most probably cause is defective overrunning clutch. | 3. Replace starter motor. |
4. A "RUMBLE," "GROWL," OR "KNOCK" AS STARTER MOTOR COASTS TO STOP AFTER ENGINE STARTS. | 4. Most probable cause is bent or unbalanced starter motor armature. | 4. Replace starter motor. |
NOTE: A high frequency whine during cranking is normal for this starter motor.
FIG. 9 STARTER MOTOR NOISE DIAGNOSIS
(1) If the complaint is similar to Condition 1, the starter motor must be moved toward the starter ring gear by removing shims from both starter mounting pads on the engine block (Fig. 10). Refer to Starter Motor in the index of this service manual for the location of the proper starter motor removal and installation procedures.
NOTE: The shim thickness is 0.381 mm (0.015 in.).
These shims may be stacked if additional thickness is required.
Fig. 10 Starter Motor Shim
1 - STARTER MOTOR SHIM
(2) If the complaint is similar to Condition 2, the starter motor must be moved away from the starter ring gear. This is done by installing shim(s) across both starter mounting pads on the engine block.
More than one shim may be required. Refer to Starter Motor in the index of this service manual for the location of the proper removal and installation procedures.
NOTE: This is a condition that will generally cause broken starter (flywheel/torque converter drive plate) ring gear teeth or broken starter motor housings.