Dave S, just did some searches on the web about the hypoid vs. non-hypoid gear oils. According to vendors like Red Line, the hypoid (GL5) oils are meant for late model cars and can tear up the synchros in an older model requiring GL4. They have a GL4 called MT-90 that is supposed to be better suited for the transmission. I may try it but am hesitant since it synthetic. Anyone on the board have any advice about the fluid to use?
