OK, y'all. I need to correct myself...sorta. What I said is neither completely correct or incorrect. I have learned that There is a lot of confusion about gear oils and the API classifications. It is extremely
common, or normal, for all GL-5 oils to claim they cover the API GL-4 requirements for gear oils. This
is a true statement. Does that make them satisfactory for synchromesh or synchronized transmissions?
NO! They meet the GEAR OIL specifications, not transmission oil specifications.
You can use GL-5 in the Raider. As I said, it is the synchros that are a problem with GL-5. Those are in auto transmissions, not in the Raider gearbox.