2003 Ford Explorer Rear Differential Whine

I bought a 2003 Explorer with the V8 and 3.73 rear end. I has a bad whine that starts at about 50 MPH. It is under warranty up to 60,000 miles so I can get it fixed but reading the forums online it seems that Ford has not figured out exactly how to permanently fix the problem. Does anyone know the background on the problem, what is causing it? Should I wait a few months for Ford to get a better handle on how to solve the rear end problems permanently. It seems that the fixes work for about 10,000 miles and the whine comes back. Any ideas??

What is the "fix" they perform?

Replace the ring and pinion gear and the convential axle grease with synthetic axle grease.

Is that a permanent fix? On alot of post I have read that just works for a while and the whine comes back.

That what I have heard is the repair and yes, it is likely to come back. I think that changing the axle grease frequently helps.

Mine was in and out of the shop for 29 days (Hmmm?) total. Rebuilt trans. TWICE, new balanced drive shaft, u-joints, balance and rotated tires...in that order. Finally believed me that it was coming from rear (2003-3:73 rear, 4.0) Replaced R and P, gears filled w/semi synth. Result? Substantially quieter overall, but still a very noticeable (To me) whine/howl at 60 MPH. EVERYTHING I have read says the trouble will return, so im buyin' the extended drivetrain warranty to get another one next year
Good luck.
Puman

I have a 2005, do I need to worry about this happening?

Me too and I hope not. Can you say class action suit.

i have a 2000 eb and mine does that too. it seems to only make the noise between 40 or 50 mph.is it something i need to be worried about as far as damaging something,or is it just an aggravation?

ok, being that i repaired these all the time and enjoyed doing it i will tell you what the problem is and how it is fixed, if it comes back it was because someone did not install the r & p correctly.

the problem is that the pinion bearings were not pressed on all the way, therefore, after time it moves and the gears start to whine, The repair is to replace all the bearings and ring and pinion, this is very easy to mess up. as some of you know if you overtighten the pinion bearing it will whine, this is probibly what most techs do, its only supposed to be 15-20in lbs drag. this is why alot are nto getting fixed, of the many ive done none have comeback, nor have any of the many my team leader rebuilt have come back, other techs in the shop HAVE had problems. but i was trained my my team leader and he is very meticulous and likes suspension and axle work so i was taught right, but most arent. therin lies the problem. but that IS the fix for the rear axle howl/whine

So what you are saying is that this a flaw that comes from the factory and the that Ford motors does not know how to install their own axles.

Seems like it should be fairly easy to correct and prevent at the factory.

is not that they dont know how its that they F'ed up

What type of whine are you referring to? I have a 00 and 02 Explorer EB and notice a little noise from the rear end and not sure if this is the same noise you are referring to? Is it normal to hear a little noise from the rear differential? Usually I hear it around 60 mph+.

If I release my foot from the gas pedal on the highway, this noise goes away. I thought it was my new tires at first, but now that I read this post I am curious. I just had a new gasket seal for the differential installed at the dealership.

Thanks!

It's a whine that starts at about 45mph and peaks at about 53 mph. It's not as noticible when accereating, is non existent when you let off the gas, and is most noticeable when traveling at a constant speed.

Xzibit A,

Thanks for the explanation. That makes perfect sense. I also read that the problem started on these vehicles because the manufacturer of the rear ends had worn out tooling that produced the gears with loose tolerances. Ford was slow to figure out that their replacement ring and pinion gears were also defective and that they were basically replacing bad with bad.

Ramtour2,
Yup! Thats it. In my first reply there is a typo...I wrote 60 MPH when in fact it is most noticeable at about 50 MPH. It is a "Wooo" type sound. Not unlike a test pattern on TV (You remember those dont you?) Initially thought I had a side window whistling. I also felt a 'seat of the pants' rumble at the speed above. Currently, (after the "fix") I have no rumble, but still very noticeable "Wooo"
Mctoy

PS; Anyone have actual experience with replacing rear diff fluid with Mobil1 vs the Ford semi-synth? Good, bad, or otherwise?

yes MCtoyu it sounds like you need a new R&P, yes it did take ford awhile at first we were replacing entire rear pumpkins, then after they figured it out, they are now overhauling them.,

as far as fluid, the motorcraft 75-140 is a very good fluid, also make sure you use the ford friction modifier.

So if I am hearing a little noise at 70 mph, then this might not be the R & P?

Can someone confirm if this is only a problem with 3.73 rear end?
What is the axel code on your drivers door for 3.73 or how do you tell if you have it?
Do all 02-03 4dr with class III trailer tow pkg have 3.73?

I am in the market for a 02-03 4dr. I drove 4-5 of them so far but have not noticed the wine while driving 45-50 MPH. Will I be able to notice it on a quick drive or does it come and go?

I believe all of the class iii/iv tow package vehicles have the 3.73. I don't think that the whine is specific to that axle. Check out TSB 05126.

i have a 2002 that definately has this problem. it is out of warranty however so when i called ford about it they basically told me to go F myself. thanks ford, sure am glad i bought your vehicle. anyways, if i take my car to a mechanic what exactly do i need to specify as what i need done? and what should this cost roughly? thanks.