i have replaced the iwe on the firewall but it still does it. i have notice it only does it on very cold days could ice be in the vacuum lines?

 

IWE stands for Individual Wheel End - and it's not on the firewall. The solenoid that controls the IWEs is on the firewall. The IWEs are located down near your front brakes on the back side of your backing plates & spindles.

As for your problem, how do you know you're stuck in 4wd? Is the light still on in your dash or are your hubs (IWE's) still locked into the half shafts? Knowing that will help us help you.

The other thing that will help you is using the Search function and looking up IWE. You'll find a ton of stuff from TN F-150 that's very helpful.

 

thanks for the respond you are correct i replaced the one on the firewall.
it will go into 4wheel but when i take it out it acts like it does not disengage all the way there will be some grinding sound in the front end so i will but it back in to 4wheel and it will go a way. like said it seams to only do it when it is very cold.

 

Like I said, use the Search function. I think you'll find that if the Solenoid goes bad, it can take out the IWEs. The grinding noise you're hearing could very well be your IWEs.