What trans oil is in a 1998 Chevy S-10 pickup 5 speed manual?
The 1998 Chevy S-10 5-speed manual transmission uses GL-4 gear oil. The specific weight (like 75W-80 or 80W-90) might be specified in your owner's manual, but a GL-4 rated oil of that viscosity range is correct. Do not use GL-5 gear oil, as it can damage the synchronizers in your transmission.