Hello everone. This is my first post so here it goes. I have a98 xlt 4x4. When i bought the truck the owner said the 4x4 was messed up and to keep it in 4high. when it is in 2wd at exactly 35mph it makes an ungodly noise from the front wheels/underneath area. (by the way it has the switch on the fly knob in dash) when switched back to 4wh noise stops and all is well. I've been driving it that way for a couple of years now. Well the other day I was messing with it and when i put in 2wd it made the noise so i flipped the switch but this time nothing happened. it won't go back into 4wh. the lights just blink. I got underneath and looked but i dont really know what to look for. I turned the front driveshaft by hand and the front axles turn but the cv's at the wheels look like they are loose. I shouldnt be able to turn the axles should I? sorry this is so long and/or already talked about. HELP PLEASE!!!