"Brownie" is a slang term used by some of us old farts to describe all auxiliary transmissions, but the original term referred to the Brown-Lipe transmissions that were sold as optional equipment on big rigs. Spicer, Borg-Warner, Saginaw, and other manufacturers also made auxiliary transmissions. In addition to your 4X3 setup, there were 5X4's, 5X3's, 4X4's, and various other combinations. Some had overdrive top gears, while others had direct drive as the top-end ratio. There were several sizes of gearboxes available, depending on the torque output of the engines they were paired with. Unless it's been lost or damaged, there is usually a tag somewhere on the side of the transmission giving a model number, and sometimes the gear ratios are also listed. I've got an older Motor heavy truck manual that has a pretty good manual transmission section with exploded views and teardown/reassembly instructions for some of the more common variations. Virtually all auxiliaries I've had experience with are non-synchronized, so you'll need to get very good at double-clutching and/or RPM matching.
One old Ford grain truck from the early 1950's that I worked on had a 5X4 main/auxiliary transmission setup, plus a manually-shifted 2-speed rear axle. It had a "tag" axle behind the drive axle, and about a 20-foot grain bed on it. The old flathead Lincoln V-8 needed all the help it could get moving that rig around! I'll bet the driver had his hands full with three shifters!
Jerry
Last edited by Hotrod Lincoln; 11/28/2009 1:37 AM.
