Guys - noticed that my selector button moves in and out along with turning to select the 4WD mode. It appears that there is an "X" on the selector that appears to be showing that by pulling out on this button you will disengage the rear differential. Just want to confirm that this action does in deed disable the rear differential?

 

Pulling the **** out locks the differential. You don't/can't use it at high speeds.

 

Yes it is the electronic rear locker

 

To be clear:
1. Pulling out the **** will engage the electronic rear differential lock that is controlled by the BCM. The BCM will engage the lock if speeds are 20mph or under. Once speed exceeds 20mph, the BCM disengages the electronic lock until speeds return under 20mph.

2. Pulling the switch at speeds higher than 20 results in nothing happening. If you leave it pulled and slow to 20mph, the diff will lock.

 

Thanks folks. I appreciate the response.

 

if for some reason you wish to use the diff locker at higher speeds and or using it to do awesome burnouts.. you can buy this little guy and you will then be able to have a locked diff for any speed you wish!

SPE Full Lock Diff Kit 11-13 6.7L Ford Powerstroke