matts227

I took my 2012 F-150 hunting last weekend and had to put it in 4x4 high for a short time to pull out of a hole. I was driving up a good logging road, so no hard 4x4 use. After this happened I started hearing a loud rattling sound on the left front tire area. There is no issues with how it roles down the road, but this is a new noise, sounds like something is broken. The noise is intermittent and only when the truck is under acceleration. I took it into Les Schwab the other day thinking there was a rock in the area of the wheel, but that was not the problem. They think its something with the 4x4 system not disengaging, even though the truck tells me the system is off.

My truck is a 2012 F-150 XLT Supercrew, 6" Pro comp lift, 36" tires. 16,800 miles

Love the truck, but not the noise…..

Thanks

BCMIF150

Independent Wheel End (IWE). A fairly common issue.

Tothemax

Does it sound like this?

matts227

Yes it is somethings like that. But it's more intermittent and doesn't do it when I jack the front of the truck up and spin the tire, only under acceleration. Sounds like it might be the IWE though. Thanks.

Tothemax

I'm pretty sure its the IWE.

Northwoods151

It could be the vacuum actuator itself partially losing vacuum. No need to replace the whole hub assembly or anything if this is the case. It's what happened to me and it wasn't pretty. I was losing vacuum intermittently then it went all together.

Northwoods151

Here is my example.

travr6

For others that search in the future......

I have a 2012 Screw Ecoboost.

Had the grinding when I turned issue and changed out the hubs/actuators/and solenoid.
The actuators were completely full of water but appeared to be new with no damage.

After changing all of these I started getting a rattle almost like a heat shield that would stop as soon as I let off the gas and resume as soon as I hit the gas again.
It would not happen sitting still. Only in motion.

So I bought a new vacuum line for the IWE and this fixed it.

I probably could solved my entire problem by draining the water and replacing the vacuum line.
But I figured if I had to go that far, might as well make the entire system new.

Logan24

Is your truck an Ecoboost?
If so, it's probably your break booster pump.
It's under your left headlight. It'll be an intermittent noise as it's only pumping when your motor is in vacuum.
Lucky for you there is a recall and you'll be covered.