Welcome to the fun. I am writting this with a smile on my face, so don't take it as mean. Click on the "resources" tab up at the top of the page and get to the TM section. Find the manuals for the M35 and down load them. Print them if you want. Then, spend the next few weeks reading them all the way through.
These are extremely simple machines. However, they were meant to be used in specific ways and until you read how to use them, bad things can happen.
Now, if your truck has a switch with a light next to it bolted onto the bottom of the dash under the gauges, that is the front axle engagement switch. That is the newer style of transfer case. Figure 1970 or so and up.
Before that, the front axle was engaged based on rear tire spin. If the speed of the rear output was faster by 6% than that of the front tires, the transfer case engaged the front shaft. All without the driver doing anything. Sprag is the name most people on this site refer to that version of the transfer case.
Because the Sprag case had to know which direction the truck was moving, there is a shaft that connects the transmission to the t-case. 1st and reverse have to be selected before the truck can move in those respective directions of travel. So, if you back up in reverse, then put the truck into 2nd to start driving. The t-case still thinks you are moving in reverse. Bad things happen. Before the really bad things though, you get wind up. Jack up on of the front tires. Stay away from the tire because if you have wind up, it will start to spin as soon as it clears the ground. Driving around in loose dirt also lets it un wind.
Wind up can happen if you let the truck coast back while sitting at a light in 1st. My 1952 Gasser pops to let me know I do this every now and then.
Read the manuals.
air shift or Sprag. I heard to many bad stories about the sprags so i stay away
If I had a duece when I was 20 it would be a daily driver.
