That's an auxillary transmission that provides some additional ranges. I don't know what a model 45 is, but it could include both underdrive and overdrive gears. Great find!


1955 1st GMC Suburban | 1954 GMC 250 trailer puller project | 1954 GMC 250 Hydra-Matic | 1954 Chevy 3100 . 1947 Chevy COE | and more...
It's true. I really don't do anything but browse the Internet looking for trouble...