Modern gear oil is fine for the rear axle, but you should use either mineral oil or gear oil rated GL-4 or lower for the transmission. GL-5 has sulfur in it that messes up the brass in the synchronizers.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
