Thanks Robert. I posted this prior to reading your post above.
1987 Starion Factory Service Manual Volume no.1 Section 0-6 Recommended Lubricants:
Manual Transmission: API classification GL-4 or "HIGHER"
Rear Axle (Limited Slip Differential): Mitsubishi Genuine Gear Oil Part no.8149630EX or "EQUIVALENT"
Any Gear oil that is recommended for use in a Limited Slip Differential will do.Equivalent means you don't have to use just Mitsubishis choice.I don't.
GL5 is specifically mentioned as a NO-NO in this TSB from Mitsu in 93, well after the service manual was published. If GL5 was ok to use, why did they spec 2 DIFFERENT fluids for the trans and rear end? Wouldn't they have saved a bunch of money and time by using the same drum to fill them both?