I thought I might put this out there for anyone who is interested. I have an 02 explorer and I had a similar whine that everyone else has described. The dealer confirmed they thought it was the rear end and that the carrier bearings needed to be replaced with a cost of around $1200.00 The dealer however told me that Ford authorizes something caleed a P05 (or something like that), which basically means that if there is a relativeley large problem and your vehicle is not coverd by warranty but under 75,000 miles, they can perform the repair for only a $200.00 deductable. (most dealerships will not tell you this!!!)

They actually found out when the diff was open that the carrier bearings were fine but they replaced them anyway, along with the pinion bearing that was looking a little questionable, all the seals, and the driver's side rear wheel bearing (the actual source of the whine) all for the deductable. In addition, they gave me a free rental car and it was done in about a day.

If anyone lives in mid Michigan, I would highly recomend Premier Ford in Grand Blanc. I have no association with them but I only have good things to say about their service department.

 

Check the speed/hall sensors on the transfer case. They sometimes touch the gears inside and create a whine/siren noise.

 

Our south Texas dealership says they have a service bulletin that adds a liquid product to rear end which allows the limited slip differential to work better and eliminates the noise. My brother in law has had it added to a 01-75,000miles- and eliminated the noise. I added to a 04 and now it is quiet again-10,000 miles.

 

Sure would like to know the name of that additive!

I know Ford used to use a "friction modifyer" in some manual transimitions, but was not aware of a rear end additive. If you can give us the name, that would be great!

Thanks.

 

Someone else might remember the name of it, but we always called it the 'Blue Stuff'... Most dealerships will know what you are talking about if you tell them you need the Blue stuff additive that goes in rearends.

I'll see if I can find the name of it...

 

I just took my explorer in on july 25th and they are going to replace the gears with some after-market parts that are stronger and match up better then the ones ford uses and they said it wont come back. We will see

 

...Welcome to Ford Truck Enthusiasts!

See you on the boards. ….

 

So, I may have a similar problem to what many have reported here ... '03 Explorer w/ 73K miles. I noticed for the first time yesterday on new pavement that when I took my foot off the accelerator at 65 mph that the car would start "thumping" as though I were traveling over expansion joints or frost heaves (evenly spaced). The problem disappeared when I depressed the accelerator again. I tried shifting into Neutral but the sound was still there.

I've always noticed variouis sounds from the rear of the vehicle, but assumed they were normal ... tires, diff, etc. I've also noticed what I described above in the past, but attributed it to road surface conditions.

Any exprience the thumping sound?

 

Got the rear end replaced on mine. NO hum

 

however, the very next day I drove it it leaked like a faucet!!!!!!!!

 

Mine rattles and smooths out if i press on the gas? Is that the same as the whine?

 

We have a 2004 Eddie Bauer "Exploder" and we are on our third rear differential. We got the original replaced at around 8K miles after it started whining horribly. The next rear end lasted about 3K miles or so, and then did the same thing. We got our third rear end at about 16K miles. This one lasted a week before the howling started up again. We now have 46K on the truck and are looking to get rid of it. We will never buy anything other than a full-size truck again.
In defense of Ford though, this is my sixth new Ford product I have purchased over the years, and the first one that has ever given me a bit of trouble.

 

I just bought a 02 and have a rummble when over 60 mph and get worse at dxcel... Are we talking about the same thing. I dont have any play in any axels diff is full but causes A vib also

 

change the gear lube in the rear axle, use only full synthetic, and add the full 7 ounces of friction modifier. you can get it at Auto Zone. The noise is the limited slip clutch, with enough friction modifier and synthetic lube it will quiet most trucks axles. might take a week to get it worked into the clutch plates.

 

Thanks I'll give that a shot