Hollow 'howling' sound 45+mph only while gas is depressed

[quaintpancake]

Hi folks,

I have a 2004 Expedition Eddie Bauer 4WD with 68k miles on it.

At speeds above 45mph (highway speed) there is a 'hollow howl' type sound that seems to be coming from below or infront on the driverside. (Maybe it would almost be like rolling a marble around a metal bowl) The sound persists only while the gas pedal is depressed (either maintaining speed or accelerating). When I let off the gas the sound almost immediately stops. Sound aside, everything about the car feels great.

Putting the car in neutral at these speeds and giving it gas does not cause the sound I'm hearing.

Does this sound like the common rear differential problem these vehicles have?
At driving speeds, is it likely that I'm hearing the sound up front because the sound is just traveling from the rear axle up front? I had my girlfriend drive it and I jumped in every seat in the car, and the sound seemed to be coming from up front.

From what I understand, if it is the rear diff I am looking at a 2k repair bill. Just looking for hope before I take it in to be looked at professionally. :-/

Thanks for any response.

 

[FordandPolaris]

My grandma's exploder made that Ford howl noise from the day she bought it till the day she sold it. Wouldn't hurt to have the fluid changed in the rear diff before actually having it replaced.

 

[mindgame]

Sounds like you may have this..
http://www.justanswer.com/uploads/fordguy4u/2008-04-23_104843_TSB-05-6-18.pdf

Since it is a TSB you may want to check with your local Dealership..
(sorry.. I dont know how these TSB work..)

 

[quaintpancake]

Thanks for the responses.

I took it in to a reputable Ford service shop.

The guy said that the noise is coming from the front differential, and that first he is going to replace the fluid to see if that fixes it.

If it's still making the noise, it will be between $1200-$1800 to repair.

 

[FordandPolaris]

Does it make the noise even when using the 2H option?

 

[quaintpancake]

Does it make the noise even when using the 2H option?

Yep, that's the only way I tested it. I was afraid to use 4H at 45+mph.

 

[mindgame]

Yep, that's the only way I tested it. I was afraid to use 4H at 45+mph.

As long as you find a straight road, you can flip it to 4x4 then take it up to 45+. I've done it many times for diagnostics for short periods...

 

[quaintpancake]

Thought i would throw this out there too...

i was driving myself crazy trying to understand why the front differential would only whine under load while the car was in 2H.

I talked to the mechanic and he said that the front differential pinion bearing engages even when the truck is in RWD mode.

just in case anyone is wondering.

 

[Moemantha]

Any luck? I have the same whine. 45 mph or so. Goes away at highway speeds.