Hey all... searched miles of the world wide web and only found one broken link on my issue. I have an 07 4.0, 5 speed, 4wd, 4wd works in high and low, light comes on, no other issues other than this! When driving on totally snow covered roads (only time I use it) 4wd bangs in and out constantly. I may get a 1/4 mile in good... then bang! slips back to 2wd spin spin... back in to 4wd... then repeat. This happens constantly rendering the 4wd useless as if it slips out of 4 heading around a corner ect.. it always only pops out for a split second then right back in to 4wd. Shift module underneath? Any ideas... thanks!!

 

Could just be shift motor needs adjustment

In the shift motor assembly is a contact wheel and 5 contacts, this is how the 4x4 Module "knows" where it is and when to stop turning the motor when it gets into position
This is adjustable, although rarely needs adjustment, so there could be something else wrong.

Pictures here of the shift motor disassembled: https://www.explorerforum.com/forums...-motor.123542/

4th picture shows the transfer case with shift rod pointed at 2WD(2H)
And you can see where it should point for 4high and 4low
And just FYI, NEUTRAL is across from 2WD, between 4H and 4L
Shift rod can only turn 270deg, 2wd + 90deg(counter clockwise) to 4high, 180deg to 4low, then it has to turn clockwise back to 2WD

I would shift to 4high and then remove the shift motor to see where 4x4 module "thinks" 4H should be, if its pointed right at 4H then problem will be in transfer case, could be worn shift rod or ??
If shift rod is not pointed directly at 4H then you need to loosen the torx screws and adjust the contacts plate so it is
You can operate the shift motor while its off the transfer case, no problem with that, to test your readjusted location, shift back to 2WD then to 4H again and check

You can also use a pair of vise grips on shift rod and tie it off to hold tranfer case in 4H and then go for a drive to see if its still jumping back in to 4high or 2WD
Shift rod must be held in correct position, it won't just stay there.

Which brings up another possible issue, the motor turns a worm gear that turns the reduction gear, shift rod and contact wheel, if some of the gears on reduction wheel are worn out at 4H location then nothing would hold it in fixed location, so it could move, and pop out of 4H, I would expect flashing 4WD lights if this was happening
So in 4H see if you can move the shift motors shift rod connector, should be locked solid

 

Thanks for the great reply... lots of knowledge. When I got the truck the 4wd wouldn't even come on so I had my mechanic friend at work open up the shift motor... it looked brand new except for an issue where the 2 little springs are and the little piece of black plastic. One of the wires near the spring was a little black and charred, and either was missing a spring or we lost it opening it up... we fashioned a new spring from a pen, cleaned up the wire and when I plugged and screwed it back on the 4wd light came right on and worked. Maybe we didn't line it up properly as u mentioned. I was careful to put it back exactly as it was when I took it out... but maybe it was misaligned to begin with.
Thanks again, will try your advice!

 

Thanks for the extremely thorough response... great info. Will try out your advice.