Dynedog

I have replaced check valve selenoid for use replaced front wheel bearing noise is intermittent goes away if you switch to 4wd I am lost help needed

Mackey

So the IWE system works on vacuum as you know and if anything is leaking in the system or damaged you would have an issue. The way I found the issue with my old truck is I bought a hand vacuum pump and tested different areas of the system to figure out what was leaking. I found one of my hubs wouldn't hold vacuum (leaking) and had to replace the hub. If you have a hole in a vacuum line, the same failure would occur. Essentially, see if you can find where the vacuum leak is, and if there isn't any leak, check the vacuum source.

SpencerPJ

Have you tried the check valve?

FordGate

It won't hurt a bit to disable the entire vacuum/IWE system it really does nothing at all for you. Ford disables it if you have a problem with the system.

Dynedog

Replaced the check valve and bypassed vacuum so only pulling on the iwes no noise just don’t have 4wd which kinda stinks

Dynedog

This on a 2020 f150 should have said that before

FordGate

With no vacuum you (can) have 4WD. The default is IWEs engaged. If you remove vacuum they remain engaged. Vacuum releases them from the hubs. Being in AWD or 4WD is still dependent on the transfer case.

As I said above, the IWEs really serve no purpose other than to complicate things.

icantdrive55

Well now, that's just a wee bit of over-simplification. The IWEs--when operating properly--disconnect the front axle(s) from the rotating wheel hub, so you're not driving the front driveline parts (axles, bearings, ring/pinion gears, front driveshaft and CV joints).

I've seen lots of posts about how it won't hurt the mileage much and I know that the upper trim levels come with the optional TOD transfer case with the 4A setting, but if I don't have to drive all those parts (that are mostly wear items) and rotating mass full time, I'm a lot happier.

FordGate

It honestly makes no difference at all. Your argument is what they used to justify this to Ford management when they adopted the system. Doesn't make it not true, it just really doesn't matter at all. Trucks have not had IWEs for most of history and never had issues like we see with the IWE system.

Also realize there is no clutch and no synchronizers in the IWE. This means every time it engages you get wear on the gears. This is every time you drive since it starts engaged and disengages after you start driving (if in 2WD).

And again, Ford disables the system frequently when there are issues with it. The official Ford fix is to disable the system. It isn't needed and provides nothing positive to the truck.

Dynedog

What is the way ford wants these disabled since I have no 4 A just 4wd and 2wd on my switch