Good day fellow Ford folks. I come today with piles of frustration and a little bit of hope that someone has been where I am right now. I have read these threads for hours and can't find anything else to try. My daughter's truck is the culprit. 2019 F-150 XLT 3.5. It has a level and 33x12.5x22. The level and wheels and tires were installed, and about 1 month later we started with an IWE grind. We have been trying for about 2 weeks now to get it resolved. Little back round.... I work at a Ford dealer in sales, and the truck is being worked on by a senior master tech. We have replaced the check valve, both IWEs, and both hubs. Swapped the solenoid and the vacuum manifold (not the correct name) with a known working truck. Smoke/pressure tested all lines per Fords pinpoint tests. All of this to have the exact same issue.

The truck will make some trips with no issue. Other times as soon as its out of the half mile warm up strategy it starts to grind. Shift into 4x4 or let off the accelerator and the noise will stop. Sometimes it can be driven 20 miles and then just at random it will start grinding.

Anyone have any thoughts or ideas for me? Anyone have the same symptoms and found some strange fix that took care of it?

I appreciate any help here. My daughter really wants her truck back!

 

I've read where the Ford "fix" was to just leave the IWE's engaged all the time? Have you tried hooking the IWE's direct to manifold vacuum (and have a vacuum gauge to monitor vacuum) or tried plugging the vacuum thereby leaving the IWE's engaged full-time to see if the symptoms change?

 

I drove it around for most of a day with a vacuum gauge taped to the window to watch what happened when they started to grind. Never did it. I have seen where a lot of people block off the vacuum lines or remove power from the solenoid to engage the IWEs full time, but I would really rather have it function properly. I may get there though!

 

IMO, you have done everything. There is a reason Ford corporate threw in the hat on their garbage system and cap them off as a fix. Thankfully a check valve 2x has cured my woes over the 5 years of ownership.

 

Just get it over with! Disconnect and plug both ends of the vacuum line going to the IWE's at the solenoid and forget about it. I did mine 5 years ago. The IWE's stay permanently engaged - just like a truck with manual hubs - and everything else works normally. Total cost was 2 screws to plug the vacuum line and one wire tie to tie the vac hose out of the way.

 

Welcome to FTE 1forford,

The real solution is what PupnDuck just suggested. You could continue to chase the vacuum issue as far as the vacuum storage tank, brake master cylinder, vacuum pump, and all related lines. It’s not worth the headache.

Having been down that road, I removed the IWEs, and plugged the vacuum lines. One of my IWEs was destroyed inside. Before that, I replaced the vacuum pump, which was leaking badly.

Simce you have new IWEs, just disconnect them and plug the vacuum lines. Yes, the from axle shafts will turn, but it wont be in 4x4 until you actually engage the transfer case.

 

I agree that would be far less frustrating. At this point it's an option but only as a last resort. The tech that is working on it is very knowledgeable and curious to find the cause, so we are fairly determined to figure it out. I think the next step is to load test and start wiggling wires with the hope that we can find something broken or poorly connected.

 

Keep us updated please, you seem to have better access working at a dealership than most of us. Most of us get next available mechanic, you get to interact with the known better ones. Good luck!

 

I have a 2017 F150 w/ 5.0 with a level kit and larger tires as well. I bought this truck about a year ago and everything was fine until last winter when I hit a bad pothole. Mine had a distinct difference in grinding when I turned to the right. Rotated the tires, same problem. Replaced the left wheel bearing and the grinding was reduced but not completely gone. Waiting to the temp is below the surface of the sun, two do both IWE's and the wheel bearing on the right. I did see a youtube video that had similar problems, and it turned out to be the upper control arm. I would be very interested to see what your mechanic thinks about the source being tie road ends or upper control arms.

 

Does your truck have 4a or just 4h/4l?

 

Just 4high and 4low. The auto 4x4 is just in the higher trim trucks.

 

Have them inspect your front diff bearings

 

Are you saying the front diff bearings could cause the IWEs to grind?

 

I think he's suggesting that it might be the front diff instead of the IWE.

 

Exactly. Seen a few where the bearings are shot and just skating across the races