Windshield Wiper - Rubbing or knocking Sounds
Group Ref.: Chassis/Body ElectricalBulletin No.: 438202
Date: March, 1994
SUBJECT:
NOISY WINDSHIELD WIPER OPERATION (PROVIDE CLEARANCE AT MOUNTING BRACKET AND/OR MODIFY CRANK ARM)
MODELS:
1993-94 CHEVROLET CAMARO
1993-94 PONTIAC FIREBIRD
CONDITION:
Some customers may comment about noise during windshield wiper operation in the form of rubbing or knocking sounds.
CAUSE:
May be due to one of two conditions:
1. The underside of the wiper crank arm contacting the upper edge of the mounting bracket during rotation.
2. The windshield wiper motor crank arm end contacting the mounting bracket on the cowl surface during rotation.
CORRECTION:
Modify the upper edge of the mounting bracket or the crank arm end using the following procedure:
PROCEDURE:
(See Figure 1 for Item references).
1. Position the wiper control switch in delay, turn the ignition key on.
2. Allow the wiper to complete one wipe cycle and when stopped on lower windshield surface, turn key off.
NOTE:
Prior to disconnecting the battery cable, the radio station settings should be reviewed, recorded and then reset for the customer prior to vehicle delivery.
3. Disconnect the negative battery cable.
4. Mark the position of the wiper blades on the windshield using a grease pencil (or other suitable marker) and remove the right and left wiper arm assemblies using the procedure found in Section 8E of the Service Manual.
5. Remove the left cowl panel, hood seal and disconnect the washer hose assembly from the cowl panel.
6. Remove the left side wiper linkage assembly attaching screw and nut (Items 1 and 2, Figure 1) disconnect the right linkage (item 3, Figure 1) from the assembly using tool # J 39232 and remove left linkage assembly (Item 4, Figure 1).
7. Remove wiper motor attaching screw (Item 5, Figure 1), and pull motor free of slots in bracket (Item 6, Figure 1).
NOTE:
The mounting bracket is welded to the cowl surface inside the plenum area. Figure 1 shows the bracket loose for illustrative purposes only.
8. Remove the right linkage (Item 7, Figure 1) from the motor crank arm using tool # J 39232, disconnect electrical connection and remove wiper motor (item 8, Figure 1) from vehicle.
NOTE:
The wiper motor grommets that engage with the mounting bracket should be inspected for wear and replaced if necessary. Use Grommet P/N 22100481.
9. Inspect the underside of the crank arm for contact marks at the "ball stud" attachment area, and inspect the upper edge of the mounting bracket for contact marks in the area shown as Item 9, Figure 1. If no contact marks are present, proceed to Step 12.
10. If contact marks are present, remove approximately 3 mm (1/8") from the top edge of the bracket using a small hand held grinder, drill motor or other suitable tool.
NOTE:
If the bracket edge needs modification, be sure to reapply a coating of Zinc rich primer and/or paint to the bare metal surfaces to prevent corrosion.
11. Inspect the end of the crank arm for contact marks, and with the crank arm still attached to the motor, carefully grind off 3 mm (1/8") from the end of the crank arm to provide clearance to the mounting bracket.
12. Reinstall the wiper motor, electrical connector and linkages by reversing the removal procedure EXCEPT that installation tool # J 39529 is required to install the wiper linkage to the left linkage assembly.
13. Reinstall the washer hose, cowl panel and hood seal.
14. Reconnect the negative battery cable.
15. Turn ignition key ON, allow the wipers to cycle on the delay mode at least once and turn ignition OFF.
16. Reinstall the wiper arm assemblies using the procedures found in Section 8E of the Service Manual, torque the attaching nuts to 32 N-m (24 lb.ft.), and inspect and cycle the wipers to ensure proper operation.
PART AVAILABILITY:
Parts are expected to be available on 3/07/94.
WARRANTY INFORMATION:
For vehicles repaired under warranty, use:
Labor Operation: T3451 (To Modify Crank Arm Only)
Labor Time: 0.6 Hr.
Add: 0.1 Hr. (To Modify Bracket)