scraping sound in 4wd.

[outtahours]

Hi, sorry if this issue has already been addressed. When i try to search the threads, the window disappears before i can type. I went to put my 03 expo in automatic 4wd on potentially slick roads. Shortly after the front left wheel started making a high pitched grinding or scraping sound. Same thing when I switch into 4wd high. Almost like it won't engage all if the way. Any thoughts on this? Only use 4wd maybe 4 or 5 times a year.
Thanks, Alan

 

[ExpeditionAndy]

It might be the IWE Relay that locks and unlocks the hubs. This video is on an F150 but the Expedition is the same.

Ford IWE system - YouTube

 

[mindgame]

ditto..

 

[outtahours]

Thanks guys, checked vacuum and it seems to be OK. Looks like IWE itself at this point.
Had to drive in snow up in the hills Saturday night, was no fun without 4wd. Lots of spinning!
Awesome truck there mindgame

 

[mindgame]

Thanks guys, checked vacuum and it seems to be OK. Looks like IWE itself at this point.
Had to drive in snow up in the hills Saturday night, was no fun without 4wd. Lots of spinning!
Awesome truck there mindgame

Thanks The IWE is a $30 part and will take 5minutes of your time