That's one way to do it. Another is to just pull the power to the solenoid. Either way works well enough.

 

Mine seem to have the most problems in cold weather so I just unplug the electrical connector in the fall and reconnect it in the spring. All the solenoids, check-valves and hoses have been replaced and the problem still persists so I've given up trying and just unplug.

 

LOL, that'll work!

 

This was the same thing I went through on my '06. Changed all of that, the vacuum box behind the battery, small hardened hoses I didn't know were part of the vacuum system, finally gave up and changed both hub assemblies and actuators and left the vacuum lines disconnected and blocked at the top side of the truck. On my new-to-me '16 I didn't even give it a chance to get to the point of the grind of death. First thing I did at the dealership was listen for the grind, first day home with it I unplugged and capped both vacuum ends in my pics above.

I remember that July/August, 5 weekends of fighting with vacuum lines and chasing down a leak, then changing out everything - twice. It was hot that year too. What a fun time. You learn a lot about the 4WD setup on these trucks when it becomes your life for 5 weeks.

 

Since this a stickie, I'll add a bit off an update. Seems Ford has come out with a shadetree hack TSB regarding the 4A TC, I'm trying to be nice and stay PG rated. Instead of actually fixing the problem, that sometimes they find, they've gone to just pulling and plugging the vacuum lines, and locking the IWEs in the engaged position. Way to go Ford, cheat people out of what they've paid for. Doesn't appear to affect the regular TC without 4A yet, but same thing can/could be applied. Happy reading.
https://www.fordservicecontent.com/Ford_Content/vdirsnet/TSB/EU - MC-10181917-0001.pdf

 

That’s probably for the best. The vacuum hubs have never been that great but Ford has stuck with them for decades.

 

Some enterprising individual could rig up an electric vacuum pump that was automatically activated if the vacuum was below some pre-set threshold.

 

My wifes 2021 limited stealth expedition does not even have solenoid or checkvalves for hubs. Vacum lines just run up into engine bay and aren’t even plugged!

 

Hmmm. Gonna have the check my wife’s Navigator now.

 

ya, starting in 2021, the hubs aren't vacuum operated any longer. From the little bit of info I've gotten, there is now a small DC motor at each IWE that works them. That line you see going up into the engine bay is a vent. A bit more involved with monitoring as well, the "system" now sees if the IWE is engaged or not.
Wednesday I'm taking my 2020 in, I'll try to get more info while I'm there.

 

Interesting. Make a complicated system even more so. I will still replace my IWEs with RCV eliminators next time this happens. I will say that my TSB corrected 4x4 worked flawlessly for hundreds of miles of driving during our week long snow event.

 

Why waste the money? Just unplug the electrical connector to the vacuum solenoid and the IWE's stay engaged all the time. I did that to my '17 years ago.

 

My reasoning is that if they begin to do it again, the surfaces where the gears meet will have been sufficiently damaged that I will want to get in there in replace them. I already wonder how much damage has been done already.

 

I searched and found a couple posts about a noise, usually when cold or after several days of sitting, comes from what seems like directly in front of the driver in the engine bay. The rattle sounds like a bicycle wheel turning with a card on it making it go "click, click, click. Stops after about 2-3 seconds. Never occurs when it's warm or as long as I start it every day or two.
My truck is a 2018 F-150, Ecoboost engine and 2WD. Much of what I read on this sticky post seems to be about 4WD. For the experienced mechanics and users, does my description of the noise match what the IWE issue is?

New user on this forum, spend all of my time on the Classic 61-66 forums.

 

IWEs don't exist on 2WD vehicles.