Once the truck is in motion, using the clutch is optional. You can simply ease up on the gas and slip the main trans in and out of gear without clutching, ditto on the 2-speed. I learned to drive big rigs on a Mack B-73 with a TriPlex trans, a 5-speed main and a 3-speed Brownie in the same box. 15 forwards, and 3 reverse ratios, and the only time I used the clutch was for starting and stopping. With a little practice, yours will work the same way.
Jerry
