Sometimes when I put my truck into 4wd and I give it gas the 4wd is not engaged. Ii will let off the gas roll back a little and I can hear it engage. Then 4wd works flawlessly. Other times I can put it into 4wd and i hear a loud pop like the 4wd is binding up then it will be in 4wd and works flawlessly. Most of the time it goes into 4wd without any pops or clunks and does great. Anyone else have this problem? It is on a 2002 f150 Screw 4x4 with a 5.4. Is there anything to check or is this common? Also when it seams to do it the most is when on a hill and trying to go from 2wd to 4wd. It also has the electronic 4wd not the floor shifter.

 

I have always heard a little clunk or pop switching my truck into 4H if I am moving or not during the switch. Going from 4H to 4L I always stop put the truck in neutral and then select 4L and here a decent pop or clunk and a somewhat of a jerk when I shift it back to drive. I have had two 2002 f150's and both did the same thing. hope this helps...

 

mine also makes a little clunk when shifting into 4lo. what i am talking about is like the gears are not lining up and is binding up. it fills like it is going into 4lo and then poping out then going back into 4lo. it only does it when it is in a bind.