my 2007 ranger fx4 when driving jumps out of 4x4 then back in and it does it in 4 lo or 4 hi what is doing this i have taken it to the dealer ship and they couldnt figure it out

 

Do you have it in 4x4 or 4 lo all the time?
On my 2004 the owners manual says to activate the lower gears only when needed. Like on slippery roads or mud or pulling conditions. I have noticed that when I leave it in 4 l o on clear roads it will let you know. fwiw

 

You need to go into the problem with a more in depth description

Dealer would have checked shift module and shift motor as those are the only electrical parts in the system.

So when you shift into 4high the 4high light on the dash comes on, correct
And when it "jumps out" of 4high does the 4high light stay on or go off?

4high light comes from the Shift motor on the back of the transfer case, so if it goes off then shift motor has moved, and thats the problem.
If 4high light stays on then transfer case itself has "jumped out", so an internal problem

You have an electric shift Borg Warner BW1354 transfer case

It uses a shift fork like a manual trans does so that part can get worn down and it can "pop out of gear(4WD)".
It uses a chain to drive the front drive shaft
When you shift into 4WD the shift fork slides over and engages the chain drive/front axle, and holds it in place

4low uses a reduction gear set so doesn't change the shift fork position, it stays in "4WD" with chain engaged, so again if shift fork was moving/worn it could "pop out of 4WD", high or low wouldn't matter

Good look at inside of a transfer case here: https://en.wikipedia.org/wiki/Transf...231PTmSOTF.jpg

Not your BW1354 but you can see the chain drive and the shift fork and the reduction gear set
Shift fork is on the large ring, it would be in 2WD now, if shift fork is moved backwards it would slide the ring over the Chain drive gear, engaging the chain drive
You can see that the shift fork rides in a slot on the ring, if shift fork gets worn down then it will be loose in that slot, and slot will also wear down, get wider, so sloppy, so might not hold it in 4WD
Front drive is on the right, rear drive is on the back left
Trans connects to reduction gear set

It is not a complicated machine