Especial86

iTrader: (1)

Turn the truck on and crawl under the truck. Try to spin the cv shafts by hand.. They should both spin pretty easily..
Now turn the truck off and try to spin the cv shafts again, they should not spin because they are locked to the hub with zero vacuum.

If this checks out than take a look at the brake dust shields and see if they are bent in and touching the brake rotor... If they are just push em in towards the engine with a screwdriver...

lewissa81

Sorry, I just saw that I forgot too link the thread.
https://www.f150forum.com/f72/how-di...m-esof-186872/

F150_Life

The sound does go away when I put it in 4wd.. If it was a dust guard issue, wouldn't the sound still be there..?

Another wrench to throw in, after I put it in 4wd and then engage back to 2wd, the noise temporally stops..!?

Mod (Ret.)

You know the area of the fault: 4x4. Now you should be able to search here for the posts that identify how to troubleshoot and repair the 4x4 system. Especial86 has provided you with a great start.

F150_Life

Update: last night after kicking it into 4wd then back to 2wd while in gear, the noise stopped. This morning it popped back on, I've pretty much eliminated the IWE solenoid and am going to start working my way down.. Possibly a hub issue. I appreciate all the feedback! I'll keep updating as I go

powerranger262

The hub is the IWE.

F150_Life

Yes, i'm aware. I was actually stating I replaced the solenoid itself, which didn't solve the issue. The clicking is still intermittent, so after my newly learned understanding of the 4x4 , it seems the only thing that could create the noise it the vacuum hub which i'll give a go at this week. Thanks again for the assistance

powerranger262

I read it too fast, now I see what you meant. That hub isn't that hard to do. Check out youtube, for all kinds of helpful videos on IWE replacement. You'll get it.

ColdinCanada

Do us a favour and follow Especial86 advice and check back in! We want to know how everything checks out. His procedure will likely tell you almost everything you need to know. To me it sounds like a partially engaged hub but you'll be able to see that pretty quickly from underneath following his advice.

mbct

Borrow a vacuum pump and see if all the check valves are still functional. They're $20 or so from Ford, but a lot cheaper than the IWE. And don't bother with the cheap generic check valves available at Autozone, etc. The inlet/outlet is slightly too small so it won't hold a vacuum. Took me 2 hours to figure out why the cheap check valve would hold vacuum at the workbench, but not in the truck!