Gear box drain and refill plugs ?

[NorthernAveo]

My bad. I have a manual gear box and the only oil recommended for it is 75w90. Never needs replacing according to the maintenance schedule.

As far as the automatic transmission, if requires ESSO JWS 3309... It's not synthetic, but from the description is probably a blend: "Esso ATF 3309 is manufactured from high quality petroleum base stocks, carefully blended with selected additives."

I still would like to swap it out with synthetic so it flows better in the cold and offers less viscosity and will allow for better cold fuel economy and less drivetrain power loss.