I heard the tell-tale whirring under 20mph and my dealership confirmed today that one of the IWEs is going. 23k miles, and I’ve had my front differential completely rebuilt and now a failing IWE. And of course, there are no replacement IWEs available anywhere in my region except for a dealership in Indiana ... which won’t release the part to my dealership. I’m being told the parts will be available mid-January, which lines up well with the availability of the frozen door lock recall parts (also mid-January) and my experience rebuilding the diff last January (three weeks to repair due to parts shortages then).

As much as I love this truck, it looks like a one-and-done affair for me. I’ve got one more big trip planned for it, then I’ll sell it next summer while I can still offer some portion of the original warranty to a buyer. Too bad; there so many things to like about the truck, but without basic reliability they don’t really matter.

Ford Customer Service: if you’re still monitoring the forum, I’ve gone from completely satisfied to completely dissatisfied with my vehicle in less than two years of ownership. I won’t be back.

 

Add mine to the list of rebuilt front diffs, just got mine back Wednesday, and it has 4A. Since I have used the 4A/4H less than 10 miles in the past 30K miles I found it extremely unusual to be badly worn to the point is was shaking the truck and moaning, while in 2H. I heard tonight slowing down from 25 MPH an awful screeching noise from the front passenger, and thinking thats the culprit that had the front drive engaged all this time.

 

Sounds like the issue I’m taking mine in for tomorrow. I also hear a whirring sound when I’m on the gas and it goes away when you let off. No idea what that would be tho. Guess I’ll find out tomorrow.
On a side note I’m gonna see what they would charge to put a leveling kit on it.

 

 

I had an on-again off-again noise from the right (passenger) front and it turned out the IWE had sheared in half. 2015 with 65K miles. It doesn't see a lot of 4x4 action. I found two Ford branded IWEs at Rock Auto and put them on Friday. Turned out the driver's side boot was about to fail as well.

 

My IWE noise is a low pitched, soft whir as I brake to a stop. I hear it just as the speedo drops below 20 mph, whether I’m going straight or turning. I don’t hear it under acceleration. It sounds like fine gear cogs spinning but not meshing. Dealership was able to ID the problem in one visit ... just waiting on parts.

My front diff rebuild last year was caused by a missing IWE vacuum hose, I assume from the factory since it was only 12k miles old then. That sound was a metallic grinding sound ... almost a constant metallic rattle. The missing IWE hose resulted in one hub locked in 4WD and the other in 2WD, which galded the internal stuff in the front diff.

Love the truck, but I’ve lost confidence in it over these two problems. Hope you have better luck.

 

Thanks for the detailed description. Hope I don't have any IWE problems.

 

Just had my front diff rebuilt under warranty. Really odd since I rarely used it, over 31K miles on the truck, can't be more than 10 miles total in 4WD. Started getting a bad vibration, and that was what they found. Now I question if the front is still engaging on it's own. Any way to tell without putting a camera on it?

 

I'm starting to notice this sound too. To me it sounds like engine braking while I slow down, but shifting to neutral doesn't stop the sound.

Edit: I should add, the noise starts only when I hit the brake pedal and goes away after I come to a complete stop. Does that mean it is vacuum related?