I recently got a 2016 F-150 with close to 100k miles. It's a Lariat with the 3.5L Ecoboost, FX4 Package, and Max Tow. It has the transfer case with the 4A option that uses a viscous coupling.

I'm hearing a roaring/grinding noise coming from the front end. I'm new to F-150s but I'm told this is not the typical sound you hear with IWE related issues. Additionally I replaced the check valve, and I had my mechanic check the vacuum in the IWE lines. They hold a perfect Vacuum. So I'm fairly certain it's not that.

I hear the noise mostly for the first 15 minutes or so of driving. If the truck has been sitting for any more than about 30-40 minutes it starts making the sound when I drive. It seems to get worse with colder weather. I can hear it mostly when I'm decelerating and below 25MPH. When I switch to 4A or 4H it turns into a scraping sound. Kind of like metal on metal.

On an IWE thread I brought up this issue and @blue2010xlt suggested it might be a bearing in the Transfer Case or the Front Diff. @johnday in BFE Pointed out that transfer cases with 4A do still turn the front diff a bit when in 2WD.

As per these suggestions I got audio recording equipment I have access to and placed a mic near the front diff and a mic near the transfer case to record the sounds from there.
Here are my recordings: (You probably won't be able to hear it on a phone speaker)

For reference, here is the sound I hear when in 4A or 4H. It unfortunately sounds more like tire noise in the video, but in person it's more of a scraping sound.

What do you think?

 

Excellent video Mike, if only everyone could that. Sure does sound like a bearing to me, seemed I could hear it best from the second mic location. Any warranty left?
Not to hijack, but I worked with a Mike Poe at DTE. Could that have been your Dad?

 

Ha ha no, Poe is not my last name. But I'm sure he's a great guy!

Interesting! So the transfer case is what stuck out to you as the stronger source of noise? To my ear it was the diff.

Unfortunately no... No warranty left... It's at 98k miles... It's a Canadian import so the warranty ended at 100k kilometers.... A while ago ha ha

 

Maybe someone else can listen to this and offer a different idea. There has been more than one guy that has problems like this. Have you checked the front diff and TC as far as condition of the oil, like water or metal filings present?

Of course someone 117 years olde, may want someone around 90 to do that.

 

When I first got it I had my mechanic check all of the fluids to see what state they were in. He said that everything looked good except for the fluid in the rear diff. That was just black he said (but he also mentioned that the factory additive tends to do that after just a couple thousand miles).

Well... now that i look at it I see the problem. My mechanic just celebrated 110... Nowhere near 90.. oh bother

 

Sorry @johnday in BFE i think I’m going to have to disagree. I think it is louder at the front diff. However I do agree is seems to be a bearing noise.

 

I think you're right, went back and listened a few times more.
Mike, did you have that picture in picture up before? After noticing that, I agree with Wayne, louder at the diff.

 

Haha no I didn't change the video.. yeah that's what I thought too.. I guess we'll see what my mechanic thinks!

 

I have a similar issue and cant figure it out. I don't have the money to throw parts at it so I've been trying to "think and diagnose" my why way through it.

I don't believe its bearing related or at least mine anyway due to it not being constant and only happening at lower speeds. Bearings would typically happen all the time I would think.

I still think its IWE related and that the IWE is working (which is why it passed vacuum test) but not fully and it takes some time for the vacuum to get the IWE totally disengaged after sitting. I just don't know if I should replace IWE, vacuum check, and solenoid or just the IWE. Until this weekend the sound would go away or stay the same when moving from 2H to 4A-4H. This weekend it actually made the noise worse when I switched. I also noticed this weekend that twice it would make the scraping sound and then I would hear a click and it would stop.

I don't know but am interested to see what you find out.

 

For sure! I will absolutely update as I find out what is going on.

I'm not going to pretend I know everything about these trucks (this is my first haha) but with my experience with bearings in other contexts, they can be fickle when they start to go bad. Sometimes they'll only make noise at low speeds, and at high speeds the vibration will sort of even out and not make noise (at least noticeably). Sometimes they'll only start throwing a fit at high speeds. Or if it's really gone it'll just screech all the time. I work in automated camera equipment and robotics, so the bearings i use are VERY small compared to these, so I could be completely off base.

I will say on my truck I almost never notice anything above 30MPH. That being said, on occasion I swear I can feel a vibration in the wheel/pedals that is the same as the low speeds. But it's so fleeting when it happens, and there's so much other road noise going on at the same time I can't be totally sure