What kind of transmission fluid go in a 1997 Chevy pickup manual 5 speed transmission?

A 1997 Chevy pickup with a manual 5-speed transmission typically uses GL-4 gear oil. However, always check your owner's manual for the specific recommendation from General Motors for your truck's transmission. The manual will list the correct viscosity (e.g., 75W-90, 80W-90) as well. Using the wrong type of fluid can damage your transmission.