Bell B40D

We have scored some of these which have been used as underground dumpies. The trannsmissions have been locked out in the higher gears and we now need to unlock them. We have the service code to get into advanced settings but that is as far as we have got.
Any assistance will be greatly appreciated. Hitachi are the agents here in West Australia and apart from the colour and the badging they are identical. Mercedes v6 motors coupled to Allison trannys and Bell diffd dropbox etc.

Bell B40D