Service Intervals: Transmission
WARNING: This page does not describe the selected car, but rather 19 other vehicles, including the 1991 Oldsmobile Bravada, 1991 GMC Vandura, 1991 GMC Value Van, 1991 GMC Sonoma, and 1991 GMC S15 Jimmy. However, it is still accessible from the selected car via links, so may be relevant.
On all light duty vehicles, check transmission fluid every 12 months or 7500 miles. On heavy duty vehicles, check fluid level every 12 months or 6000 miles. Periodic draining and refilling is not required.