Last night I was out playing in the mud and tried to engage 4x4. It hasnt been engaged in a while. When I did i was still moving and clicked it over. The 4x4 light popped on. It didnt engage until I let go of the throttle and slowed down and then with a thud it engaged. I thought I heard a bit of grinding and then a clunk. It worked fine, just makes weird noises when going into 4x4.

 

my truck has done this a couple times if i haven't engaged 4x4 for awhile, but It still works fine and haven't had any problems so I'm sure its normal.

 

Not sure the way the t-case works on these Fords yet, but I know on a Chevrolet that especially when in loose ground (i.e. mud) the electronic hub/gears need to be lined up correctly before it engages, which will sometimes cause a delay and a clunk when you are not expecting it.

 

thats what I was thinking with the alignment. Because I was in ruts moving about 10mph and sliding all over when I engadged it. It still performed flawlessly though.