Ford 4x4 issues

[GFNER]

Thought I had this fixed until yesterday. Put my 03 in 4x4 mode but have no four wheel drive. I replaced the vacuum accuator on the firewall, blew out vacuum lines with a little compressed air and acknowledged that it was moving the arm at the differential in and out.Switched 4x4 button in the cab on and off about a dozen times and finally kicks in but is intermittent. Any one else had this problem fixed? I'm pretty sure this is a common Ford issue.Any help would be appreciated. Thanks!

[Scott K]

F150 I assume? It sounds as though the axles are locking in, but possibly the shift motor on the transfer case isnt engauging the transfer case into 4x4

[fishing tech]

When you put it in 4x4 does the light on the dash come on? If it is intermitent or it doesm't come on it is more then likely the shift motor. If the light comes on and the 4x4 doesn't work you are looking at a solenoid or axle problem.

[Macgyver55]

I just ran into this on an 03 that I worked on recently. The light came on and stayed on but the front axle didnt engage. Turned out the shift fork actuator rod was corroded and binding and would only work intermittently.

This was inside the rubber bellows cover where it connects to the actuator. Cleaned it up and lubricated and it worked like a champ. I have heard that there is an issue with the shift fork bending or breaking on these also but

have not run into it as of yet.