I know someone here can help me. My problem originally started as roaring and occasionally grinding sound coming from left front. Dealer replaced the solenoid and check valve. Issue never went away so they said it was the IWE but wouldnt be under my warranty.

I replaced the IWE myself last week and noise is still there. Last night I replaced the hub and that's when I noticed that the axels are staying engaged all the time. When I installed the hub it would turn free but once I shifted to 4H and then back it would never disengage.

Thoughts?? This is driving me crazy. I've read all that I can find and replaced actuator, solenoid, check valve, and hub. I'm currently checking vacuum lines (just went and got a gauge) but then I'm completely out of ideas.

 

first, simplest question i could think of...... did you get the vacuum line correctly installed onto the IWE when you replaced it? There are 2 lines connected, the vent line is slightly smaller so they really only go one one way, but they need to be clean and properly seated.

I would verify that the vacuum line vents are clear as well. If those are clogged, the IWE will not actuate correctly. If you get a vacuum gauge/hand pump you can test the system easily. Hook the gauge to each vacuum line where it would connect to the IWE and measure vacuum applied from the engine (through the check valve, solenoid and all tubing). With the engine idling in 2WD you should see about 19-21" vacuum. In 4WD you should see nothing. With vacuum applied to the IWE, it overcomes spring tension and disengages from the hub. With no vacuum applied, the spring will engage the two. We need to make sure that you are getting correct vacuum from the engine first.

If that checks out correctly, then i would apply vacuum to each IWE one at a time using the gauge/hand pump. At around 15-16" vacuum, the IWE should disengage, and the axle will spin freely. Pump up to about 19-20" vacuum and go have a beer. If it is holding when you get back, the IWE is good. There is an acceptable loss, but it shouldn't be noticeable in that short of a time. I would start on the side you suspect to be at fault.... it is possible it had a bad seal and then maybe damaged the seal on the new one when installing. Repeat this step for the other side as well.

Now if that is also good, then i would install your vacuum gauge at the solenoid "outlet" line, which runs to both IWEs. Again, apply 19-20" vacuum and go have a beer. If it does not hold, that would tell me you have a leak in a vacuum line somewhere (can be tough to find, most simply replace the lines entirely). If it does hold, then i would be at a loss, since up to now we have tested each IWE independently, measured the vacuum applied from the engine, and applied hand vacuum to test the lines with the IWEs.

Post back what you find and we can continue from there!!!

 

Lets start with the fundamentals.

The hubs will remain locked until vacuum is applied -meaning you must have the vehicle running for IWE to release.

From how you wrote you post, it doesn't sound like you had teh vehicle running? I'm reading it as "I removed the hub, replaced it and the hub is locked".
Not....
I replaced the hub, started/drove the vehicle and the hub is still locked.

My apology if I misunderstand.

 

You should also check the engine vacuum lines, my old truck had a similar issue. On Mine the right side iwe would randomly engage while driving, I found a cracked line going to the iwe solenoid from the engine. It would depend on how the line sat it was a small crack so every once while it would open up and cause the iwe the engage. Also there was an updated solenoid with a rain hat on it. The rain would get funneled off the windshield into the solenoid causing issues

 

What year truck? What trim package?

 

ok so I’m also looking for help with my IWE issues on my 2015 f150 lariat crew cab 3.5. I have checked all my lines for pressure and holding pressure, the vacuum pump pulls 22 inches but this front line in the picture only pulls 15”. Sometimes other iwes’s work but most of the time once I start driving and get past about 15 I can hear them try to re engage and then if I switch to 4wd you can hear them engage and the grinding stops, but then going back to 2wd they don’t fully disengage. Solenoid works properly, check valves work. WHAT IS GOING ON??? Is the front line pressure to low? Are my Iwe’s bad? It seems worse when it’s cold and I live in central Utah. ANY help would be greatly appreciated!

 

Have you found a solution to this? I am currently having the same issue. Except I’m pretty sure the noise I hear is in my differential. I replaced my cv axels on both sides the iwe solenoid, checked all vacuum lines I replaced the iwe actuator and the wheel hub assembly on the driver side and the axel still spins in two wheel drive. I bought a vacuum pump today and hooked it straight to the new actuator I can hear it pull away but my axel still spins. I’m at a loss of what to do.

 

did you ever figure it out on the experiencing the same thing?