I had to swith to 4X4 many times going to work. Going up a steep grade. Ice and snow covered on I-15 felt the rear end losing traction and felt the rear tires slipping. Going up that grade, I almost lost it a few times. Traveling around 40-45 MPH. Switched to 4x4 and problem solved. But I never switched to 4X4 on dry pavement.

 

I setup an appointment with the dealer tomorrow to come out for a drive with me and listen to this sound. I just want to make sure its all good.

I'll let you know how it goes.

 

I just realized I never followed up on this thread...

I had the dealer check it out. They too thought it was rather noisy. We took another truck from the lot out and it also made the same noise, just not as loud as mine. They contacted Ford Canada and they said it could be "driveline wind up" and to just drive it and see if it gets worse.

Tried it out again today on a gravel road and the noise is still there. Everything seems to work fine however, so I'm just going to see how it goes.

 

I have a 2010 Raptor and it has the same whirring noise you describe when in 4HI. I've allegedly had the truck up to 80MPH in the desert in 4HI. No problems.

4 Low has a "geary" noise too.

Both are normal.

 

I don't understand - 4x4 should sound different as an additional set of gears is operating .It may be a normal sound you have to get used to .If other similar trucks have it , it's a 'normal' sound.

4x4 only for low speed ?? I guess I've been driving wrong for the last 30 years !! On the interstate in snow 4x4 is used .Stopping ? We now have ABS + intellegent driving.

 

Okay, so I just made a video demonstrating the sound I'm talking about...

 

That doesn't sound serious .2x4 has gear whine from one differential and 4x4 has gear whine from two differentials !! Remember that you're on dry pavement putting undue stress on tries and gears especially if you were turning.

 

Thanks. But just to clarify, the sound is exactly the same driving in a straight line on gravel roads and other loose surfaces. I only drove on pavement (and in a straight line) for this video.

 

Yup it's the same noise I get in my Raptor in 4Hi when running.

 

Cool, thanks. Hope you're enjoying that Raptor!

 

My 2009 makes the noise you describe. If you open the door, and listen below, you will notice that the transfer case is producing the noise.

Normal.

 

^I 2nd that (on a 2010), you're probably good

 

Thanks for the tip. I opened the door and you can really hear that the sound is coming from the transfer case.

Glad to hear its normal.