Mitsubishi Repair: Transmission, automatic transmission fluid, auto parts stores

Question
I am about to replace my transmission on my 92 eclipse. It is a GS 1.8 manual. Do I fill it with automatic transmission fluid, or just gear oil?

Answer
Randy,
You should be using gear oil.  Your owners manual will tell you the viscosity rating appropriate for your car.  For these transmissions, Mitsubishi prefers you use a GL-4 rated gear oil.  But those gear oils are not easy to find at your local auto parts stores.  Most sell GL-5 rated gear oils. Those are fine to topping it off, but if you want the best performance and longevity out of your transmission, get a GL-4 oil.  You can either order those online, or visit your local dealership.  Chrysler most likely carries GL-4 gear oil as well.
Good luck!