Hey guys, I just tried my 4x4 for the first time this year with no luck. It's iced over in the Dallas area and I gave her a try, but the front wheels aren't pulling? I have an electronic shift/automatic in my 2004 Lariat. I can hear the transfer case engage in 4 high and the transfer case changes the rear axle speed when I go to 4 low, HOWEVER, the front axle won't pull in either setting? Any ideas? The rear wheels spin and the front wheels won't in either 4x4 position?

 

I have actually determined that the transfer case is engaging and the front shaft can not be turned by hand once I have selected either 4x4 position on the switch, which tells me that the transfer case is doing it's job. However, I have only one solenoid on the firewall on this 2004 model? It has constant vacuum to the bottom port. If I unplug it from the solenoid and use a piece of plastic tubing and supply vacuum to the top line going down to the axle, it still does not apply the axle? My best guess is that the vacuum actuator on the axle itself is not working? Any ideas, or should I just replace the unit on the front axle?