I have a 2002 2wd Excursion. Just picked up a 2000 F250 4x4. Its my first 4x4 (really my wife’s new ride) and I’ll be using it to pull my boat. How does the 4wd work? The locking hubs DO NOT MOVE by hand. Is that normal? I switched it into 4wd LO in a parking lot and hit the gas and there was a clunk after about 20ft forward. I drove it for a minute in the lot then turned it off and heard it click. Then tried to go to hi as well as low again and never heard another click or clunk. I don’t think the guy we bought it from used the 4wd much. My wife pulls the boat out of the water and I would like to have the 4x4 engaged to help her out. We actually bought the excursion to pull a smaller boat we planned to buy and my wife wanted a bigger boat and although we have had zero issues, I like to be a little more over prepared. Boat is 9000-10000 pounds on the trailer with fuel. Our ramps are REALLY steep on the Ocean side. The fresh ramps on the river are also slimy so having 4x4 is a plus. Dude told us the hubs don’t need to be locked for limited slip. Only if you want them all rolling in the same direction regardless of traction. That reduces turning radius, which I recalled reading years ago. Makes sense. Please confirm. Is there a way to tell the 4wd is actually working besides the idiot light? Any idea what the clunk and click when engaging and disengaging was, and why it only did it on 4x4 lo, and why I couldn’t get it to go back into 4x4 lo again? He also said you could engage the 4x4 while driving down the road. I recalled as a kid we would stop to engage lo which was all we used since my dad only ever used it to pull people out of mud. It was a shifter on the floor back then in a 79 Ranger that was brand new. Thanks for the help. I posted in Excursions cause I already know you guys.