Hi
As the fluid is red, it's quite likely to be an ATF, but there are normal gear oils that are coloured.
I would use an MTF for the gearbox and the best proven options are the Red Line MTL, Amsoil MTF or Fuchs Sintofluid. The Millers TRX 75w-80 and Motul Motylgear are good alternatives.
http://www.opieoils.co.uk/c-670-75w-80-75w-85-mtfs.aspx
Depending on the diff fitted, you might need to add some friction modifier.
http://www.opieoils.co.uk/p-6320-red...-additive.aspx
Cheers
Tim