Section 108 (Wiper System/Washer System - G Series Vans): Overhaul
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 1991 GMC Vandura Special, 1991 GMC Vandura, 1991 GMC Rally Camper Special, 1991 GMC Rally, and 1991 GMC Magnavan. However, it is still accessible from the selected car via links, so may be relevant.
Repairs to motor/gear box section of wiper assembly are limited to switch, plus external parts, crank arm, spacer and plastic seal, and output shaft seal. No other overhaul procedures are given by manufacturer.