I had my truck in for the god damn IWEs not three weeks ago, had to make do with a stupid Focus as a rental in a major snowstorm. Now here we are less than 1000 km later and the clunk is back AGAIN.

I am getting pretty fed up with having this dealt with every month. I drive in 4A pretty much all winter, and I bought the truck specifically because of the 4A function. I know there's an IWE delete kit out there but doesn't that basically convert my truck to 4HI only?

 

I feel your pain and sorry to hear that. The system is wholly unreliable. It’s the worst 4x4 system out of all the manufacturers. Hopefully for 2021 it’s changed.

 

The IWE deletes simply keeps the front shafts turning at all times. Certainly doesn't hurt 4A/shift-on-the-fly functionality. It will likely result in a small drop in fuel economy (since you've got more stuff turning, thus more drag) and some people claim it may increase driveline wear by a small amount.

 

Whats this clunk being mentioned?

I have a 2018 Lariat and ya...in 4A most of the time or in 4Hi as its icy and lots of snow here.
I gotta say that so far my truck has switched in and out of 2wd to 4wd to 4A without any issues or sounds!

 

I had one IWE failure in the over three years of ownership now on the passenger front side. It was a bad check valve which they replaced to the newest version. However the tech was telling me that's usually the case and they haven't seen many come back after the fix. He stated though that if the truck keeps coming back the only reliable way to correct the issue most of the time is to replace the entire system, lines and all. Even the smallest leak or failure can be the biggest problem.

 

The only thing that gave me issues on my IWE was the check valve. 50k miles and plenty of 4x4 use and no IWE issues.................what are these problems of which you speak?
I did IWE delete on my old 4runner...with manual locking hub replacements. Which was only a PITA when I needed 4x4

 

What is it that destroys the IWE's? is it a vacuum problem?

The vacuum hubs on the late 90's Rangers and Explorers were such a disaster that Ford went to full time engaged in 2000 (or 2001?), and as far as I know kept it that way until both those trucks were discontinued around 2010. My 2002 has full time engagement in the front hubs, hasn't been a problem. Why Ford went back to vacuum hubs is beyond my reasoning, probably for fuel economy numbers.

I was fine with manual locking hubs I had on my 87 F150, not as convenient but I could live with them again if needed.

 

Okay, you are frustrated -I get it.

First, driving in 4a or 4wd is actually better for the IWE than only in 2wd. So maybe it's not the 4a issue, or the IWE issue. Not if you are buring through them in a month. You probably have other issues, somewhat related.

Who did the work?
Who is doing performance checks?
What is the outcome after a check that is leading to replacement of the IWE?
Has the wheel bearing assembly been changed out on the same wheel as the failed IWE?

If you understand how the system performs on our trucks then you will know the IWE is drawn inboard when in 2wd via vacuum and is held there. Things in play are vacuum hoses. Electrically operated solenoid. The actual IWE and a check valve. Any one of those that fail will begin to cause problems.
Once the user shifts to any mode not 2wd, hubs are locked. It's virtually impossible to wear out the teeth on an IWE as it is now locked to the hub, not under vacuum and cannot slip off the hub gear.
Of course it only takes one bad fail for the teeth to get ground down. So I do get that. Which makes me circle back to the top of my message where you likely have a failed/failing component in the system. See my check list and indicate what has been done to prove the system is working properly. IWE's don't really fail, but the system can toast an IWE. However, if your IWE is taking in water and freezing, then yes that is a very good reason for a failure.

If your IWE is currently junk and you are considering a delete kit, save yourself the time and simply disconnect the electrical connection from the solenoid and bam, delete kit is essentially installed. You will no longer pull vacuum to the IWE, it will stay fully engaged and your problems will be solved and you can be a happy driver through eternity.

 

i've deleted with rcv delete for over 60k miles now no complaints, like it over just unplugging because they have more teeth connecting to the hub with less plastic parts that can break. Can't really go wrong either way tho.

 

I'd argue something else is wrong. Maybe a pinhole leak in a vac line, faulty check valve, faulty solenoid valve, or moisture..
I had 1 failure with a cracked inner spline but that was after 220k miles..
The design is sill the same, and the system works good.
You just have to know how to test it with the front wheels off the ground engine (running) vac and (engine off) no vac.. It's usually easy to diagnose..
...Sounds like they are just throwing parts at it and they keep missing....