when i turn in four wheel drive it makes a bangfrom the front like it is poping out of gear and when i back up in four wheel drive it just growls and dosent move any help would be great .

 

Usually it is the IWE's. Integrated Wheel Ends and the solenoid on the firewall. New solenoid at the dealership comes with a cover over the top to stop water intrusion from the cowl that goes into the vacuum lines. Wheel ends are located back side of wheel knuckle, held in place with three bolts. Solenoind is located on firewall behind the battery. Check your vacuum hoses and apply vacuum to the hose that goes down to the wheel ends. Does it hold vacuum? If so than try moving truck in 4wd to see if it makes noise. If it does than your wheel ends are faulty. If not than it's the solenoid. Hope this helps.

 

the left side does not hold any vacum does that mean that the acuator is bad or the hub or both the guys at the ford garage tell me to replace both

 

the left side does not hold vacum do i need to replace the wheel end and the hub that is what the deler ship says to do

 

If it were mine, I would replace both IWE's With the upgraded solenoind. The solenoid comes with the little cover over the top of it. I did this with my own. Hope this helps!

 

You can also just replace the effected one and see if the other one is bad, but usually what happens is when one won't hold vacuum it may slightly engage the other one causing it to grind the teeth off of the one that will hold vacuum.

 

so replace the left wheel end and the right wheel end and leave the hub and bearings alone. also replace the iwe's silinoid that is on the fire wall.
do you know why the garage said to replace the wheel hub to ?

 

Bearing by inspection only, pop your upper ball joint apart, may have to undo tie rod end from knuckle, center nut for axle(behind cover). Pull knuckle down, cv shaft out of the back of it. There is a gear on cv shaft, gear on back of bearing. The IWE always rides on the cv shaft, when engaged it slides to lock cv to bearing. Lack of vacuum, weak vacuum allows for partial engagement, thus grinding the gear on the back of bearing/hub. Once you take the IWE out you can determine if you are gonna need a bearing.