Gulfsuper Great truck !! Never did hear anyone try to help you with your 2-speed shifting. I think you will find if you take-off in low axle then shift your control-with tension (power)on the driveline when you let-up it will shift to high axle this would be in high gear. Maybe at 25 MPH next to downshift just slow down to 10 MPH or less with tension on shift and when you let-up will go to low axle. You can then learn to 'split shift' your gears when loaded !!! Big Fun for Big Bolters !!!
