I have a 99 f150 4.6 4x4 5 speed so I had it in 4hi doing about 45 50mph out of nowhere here a clunking noise and smoke came up through the shifter boot and now when I start it and foot is off clutch it chatters like something is not engaging has a Lil trouble from 1st to 2nd but other than that shifts fine and does not chatter in the rest of the gears 4 trys to pop out every now and then I do not feel any vibration in the transmission shifter but can feel it bad in 4x4 shifter any ideas thank you.

 

Sorry, why were you doing 50 mph in 4 hi? If you can go that fast there is no reason to be in 4x4. I cant help you with the other issues. Good luch