SCRATCH IN WINDSHIELD FROM WIPER ARM RAMP FINGER

SUBJECT: ARC SHAPED SCRATCH IN WINDSHIELD FROM WIPER ARM RAMP FINGER

VEHICLES AFFECTED: 1987-90 L CARS

Some Corsica/Beretta models have been diagnosed as having arc shaped scratch marks on the right side of the windshield. The scratches are caused by the wiper arm ramp finger rubbing on the windshield..

The ramp finger rubbing on the windshield is caused by opening the hood assembly far enough to contact the right wiper arm assembly. This slightly deforms the wiper blade superstructure which in turn allows the ramp finger to contact the glass and scratch the surface. After VIN breakpoints LY147121 (Wilmington) and LE165062 (Linden), wiper arms used in production have the ramp finger reduced from 16 to 10 mm, refer to Figure 1. This change will reduce the incident rate, however, if enough deformation exists the ramp finger may still contact the glass.

To stop the ramp finger from contacting the windshield, perform the following:

Remove right hand wiper arm and grind down ramp finger to 10 mm (0.4 in.) (be sure to round off ramp finger to eliminate sharp edges).

Remove suspect wiper blade superstructure.

Place wiping element on clean flat surface.

Apply 6.12 N (22 oz.) force at centre of wiper blade superstructure - near pin connection (to simulate wiper arm load).

Measure from flat surface to centre of pin hole, refer to Figure 2.

If dimension is less than 22 mm (0.87 in.) replace wiper blade superstructure with GM P/N 5049731.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.