I have a 2005 5.4 3v Expy. Eddie Bauer.
4X4 110,00Mi. Non airbag Suspension.

I am having a moderate, but constant "buzz" which sounds like it is coming from the front end. The noise level increases with speed. It is present in all 2H/AWD/4H/4LO Settings. And as of 2 days ago, an odd "Whoomp" noise that sounds like a bad tire.... may or may not be a related noise ...

So far I have Replaced Both left and right Wheel Hub Bearing Assemblys. Inspected Both vaccum Hubs, and Confirmed that the hubs are free with engine running, in 2wd, but do lock in 4wd. I have also replaced the IWE solenoid. I checked the oil level in the front Diff.

And ideas??? I was assuming that the front Diff/Drive shaft does not turn in 2WD. Is this correct?
I guess I should start working my way back...

 

Have you ruled out the noise coming from the front radio speakers?

 

It is certianally coming from the drivetrain... The noise really sounds like a bad wheel bearing, Not that new is always good. But it sounds the same as before replacing both.

 

When in 2WD the vacuum hubs are disengaged, this leaves both the front axle and driveshaft not turning. So that leaves the noise as being at the wheel areas. What if you swap the front tires with the rear tires, does the noise move with the tire or does it stay up front?

 

The noise Stays up front.. I am leaning towards the Transfer case. Just picked up some fluid to do the flush... I may REreplace the front LH wheel hub also... The Noise is constant in all 2WD/4WD settings.

 

I flushed the Transfer case fluid. No help. I had my wife slowly drive the truck while I looked under it. In 2wd the front CV's are turning, and the Driveshaft is not. When I jack the truck with the engine running and spin a wheel the CV's are free.

Any Ideas? Perhaps a 4x4 airbag not holding vaccum? Anyone know anythig about the Check valves?

 

I have a similar issue, changed the front hubs same issue. Here's my thread: https://www.ford-trucks.com/forums/1...hat-is-it.html. Good luck!

 

I have a low frequency noise/vibration at the front end that came up recently on my 2005 Ford Expedition Eddie Bauer 4WD. It happens in 2WD/A4WD/4H/4L and gets louder as the vehicle gains speed.

I jacked up the front wheels and did the actuator tests on both wheels. The actuators lock when engine is OFF because when I turn the wheels by hand the CV axles and front shaft turn. When the engine is ON, they disengage on 2WD because when I turn the wheels by hand the CV axle and the front shaft do not turn.

I lowered the front end, jacked up the rear end, started the engine, put the selector in 2WD and shifted to Drive. The rear wheels rotate normally. However I noticed that the front shaft is also turning. It seems that the noise/vibration is coming from the front shaft turning in synch with the engine.

In 2WD, the front shaft is not supposed to turn. What is the remedy for this problem? Anything I can do to fix the transfer case? Any opinion would be appreciated.

John

 

If you look a few posts up you'll see a link to my thread that describes the problem I had. It sounds very similar to the problem you are describing. Turns out the fix for my Expy was a right rear hub assembly. Hope that helps.

 

Thanks for your quick response. I have gone through your thread which sounds similar to my problem. I will take a look at both rear hub assemblies.

Is the front shaft is supposed to be solidly engaged in 2WD? I have gone through many posts which say that it is not supposed to rotate but light friction could make it rotate slowly. But some posts say that the front shaft is engaged all the time.

Thanks.

 

I can't recall for sure, but I think the front drive shaft did rotate, but at a much slower rpm of the rear when I had it up in the air tryin to troubleshoot the problem in 2wd. And of course it rotated in 4wd like it should have.

I had also removed the front drive shaft and the axles and still had the same sound. I ended up changing both front hubs with no help. In a last ditch effort I changed the right rear hub at something like $350 before going on to the rear diff.

 

I had a similar noise while driving at freeway speeds. It wasn't a strong humming vibration when turning or going around a bend but it was definitely present. After changing out two front hubs and a front axle shaft I checked the rear left hub. Completely dry and grinding. It's very similar to the front but no vacuum actuator ring and much more heavy duty. As such it also costs 2x what the front does. That fixed it though.
Good luck.

 

I HAD the same problem.
I read all the forums, watched guys replace alot of parts and never fix this.

My dealership had a TSB (technical service bulletin) about the symptoms everyone is having.

I also, did my front rotors, pads and new tires...
Still there.

Dealer replaced the wheel bearings,
still there,

Transmission guy inspected a resealed the transfer case.
still there.

Then the TSB was found! ...JACK POT!!!!

Basically, the front drive shaft always turns and spins the front ring and pinion. This creates a condition where one side of the spider gears spins faster than the other side. ????? thats the noise???? YES!!!!!!!

O.K. how do you fix it? it is a spring that goes between the gears and keeps the spider gears from spinning at different speeds. NO MORE NOISE.atriot:

Parts they used to fix it are listed below.