I've got a question for all you smart folks out there. I have a 97F150 4.6l auto with the manual 4wd shifter. When i use the truck after it sits all night it takes the 4x4 a while to click in. it's almost like it has to warm up before it works. It sucks though after a snow storm and i have to rock my truck back and forth because 4wd didn't come on. After a couple of minutes of driving it will work fine. Any ideas??