GeekMan

My 2014 4x4 F150 has a roaring sound easily heard above 20mph and higher. Louder with more speed like off road tire roar. To eliminate any rotating parts at front wheels I lifted rear end. With rear wheels off ground and traction control disabled, I started engine and put into gear. I pressed gas and as I got to 20mph or so on speedometer I could hear the roaring. I was also setting flags and warnings because I was not moving!

So, this makes me think front diff, rear diff, drive shaft or maybe a bearing. Before lifting rear I suspected something at front wheels. A dealer mechanic thought front wheel bearings and quoted me $1200. I said maybe later.

Is there a common failure with this symptom that I should focus on?

montanaman

It's not going to be the carrier, unless you have a very uncommon failure, I think bearings or a CV joint or something.

A person engages that front differential so little that you shouldn't have any problems there yet.

redcelica

Ive got something like that, although I feel it more than hear it. 118k on the clock on my '12. Post back when you find out what it is!

Turbo Kidd

Ditto, can't figure it out either.

snel1698

So I had the same issue as you. A rumbling noise starting at about 20mph and increased with speed that I was certain was coming from the front end. I figured it was the wheel bearings so I replaced those... to no avail. I was stumped because nothing driveline related in the front rotates when in 2WD other than the wheel bearings. The frt driveshaft, diff and CV axles are stationary in 2WD so this easily ruled out any of those as my issue was in 2WD. I realized that when I engage 4WD the rumbling goes away immediately and comes back usually when put back in 2WD. So looking into it and figured out that the IWE's were not disengaging like they should. They are vacuum operated and the default position is engaged. I found the passenger side was sticking. I could switch in and out of 4WD a few times and it would usually go away. My problem started intermittently and turned to being more permanent. There are a few components to check if your IWE's are faulty. It could be an IWE, or IWE solenoid, check valve or vacuum line. My problem was a RT side IWE that had a large chunk of plastic broken off. I replaced both IWE's and problem solved. An easy way to check your IWE function is to start the truck, leave in park, in 2WD and jack up the frt tires enough to just rotate them and check to see if the CV axle is rotating also, check both sides. If so, you have a problem. If your IWE's are working fine the only other thing it could be is the wheel bearings...if its coming from the front. If you're going to replace wheel bearings, do the IWE's as well. They're cheap and easy to do. They are pretty flimsy so you'll understand why they would fail.

Driveline vibrations are almost always either bad wheel bearings or U-joints in the driveshaft. Check those before checking carriers, pinion bearings, diffs, t-cases and such as those are not common problems.

ALREALLDAY

My 2016 3.5 4wd had the roaring sound as well. I was only getting 14mpg and the sound was definitely coming from the front. Took it to the shop and they replaced the carrier and pinion bearings, the noise went away and I started averaging 21mpg.

rmt15n

I had the same issue with my 2013 Lariat f150 with 120,000 on the clock. Mine was noisy about 35-45 mph whether in 2wd, AWD or 4WD. Replaced both wheel bearings, both IWE’s, switches, check valves and all lines. Turned out the issue was front differential bearings were shot. What I found out from Ford is Lariat and above transfer case turns the front differential at all times whether in 2 or 4 WD. Different transfer case than XLT and below. So the only way to eliminate my issue was to remove the drive shaft from transfer case to front differential or rebuild front diff-which I did, Problem solved no noise at all. Hope this helps to differentiate transfer cases.

ALREALLDAY

Mine is a lariat and only 35k

snel1698

Where did you get your information regarding transfer cases spinning the frt driveshaft all all times regardless of being in 2wd or 4wd? I have researched a great deal and have not ever heard that....except on GM's. IWE's disengage at the wheels and the transfer are disengages at the output shaft hence the CV axles are stationary in 2wd. This means that the frt driveshaft would also be disengaged as they are directly connected. I have a 2012 FX4 and my frt driveshaft and frt diff are NOT spinning in 2wd. This was the whole selling point of the IWE system and what set it apart from competitors. If you have a fault in the IWE system then your hubs will be engaged and you will be spinning your frt diff which will spin your frt driveshaft. This will cause reduced gas mileage and decrease your turning radius and was the cause of my driveline vibration. I did look into carrier and pinion bearings and I am glad that wash't my problem as it sounds expensive. Here's a short video explaining IWE's.

rmt15n

Don’t shoot the messenger please. Lariat and ABOVE have a different transfer case than XLT and below. I know for a fact because not only did the Ford tech line confirm this , we also put 3 Lariats on the rack to confirm. I know all about the IWE system in and out and how it works. Just trying to differentiate that not all F150’s have the same transfer case.

My advice on all this is if you have a Lariat or above change front diff fluid at 25,000 or 50,000 mile intervals. If not you risk costly repairs down the road. Just a suggestion