Rear End Howl

2003 Explorer XLS 4.0L/Auto
Auto 4x4
43,500 Miles


I just bought this explorer about a week ago, and i just took it out on the freeway for the first time yesterday. I noticed from about 55 to 65mph there is a howl from the rear end. It starts at a very low freq and very quiet at 55 and gets progressively higher in pitch and louder all the way up to 65 and then it just stops howling. It only howls under load, so if im in the range, and i let off the gas, it stops howling. Ive searched, and i cant find anything directly relating to this. As i understand it, the common rear end whine or howl is caused by the limited slip rear end and a lack of friction modifier from the factory. I dont think i have a LS rear end because i dont have the towing package. Well i dont think i have the towing package, my hitch reciever is only a 1 1/4 inch.

I was wondering two things:

1. If i just ignore the howl, will there be any real damage done to the rear end, or shorten its life span. I can live with the howl if it isnt doing any damage, its not very loud.

2. Is there anything i can do to lessen or eliminate the howl, or would this be a warranty issue, i do have a RoyalShield warranty from the dealership i bought it at, but only for 3 mo / 4000 mi (it came with the purchase of the truck) so if it is, i need to take care of it soon.

It bugs me because i used to wheel jeeps and i know that howl is from poorly setup gears, and at the very least the excessive lash shortens the life span of the gears and at the worst, ive seen rear ends completely lock up because of wear incurred from excessive lash.

TIA

Ron

Welcome to this forum! Did you try rotating the rear tires to the front to rule out the possibility of belt shift? Check the rear U joint, and fluid level in the diferential.

I believe there is a TSB, possibly a recall on the rear end noise, but I don't know if there is any solution.

MountaineerGreen said:

I believe there is a TSB, possibly a recall on the rear end noise, but I don't know if there is any solution.

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My parents have an 04 and they replaced the entire rear end.

I would get it back to the dealer because it is most likely the rear gear. It is common in the early gen IIIs. It is a defect from the manufacturer (gears not set up or installed properly) It will get worse and may be expensive to fix.

Read this thread.

It sounds like you definately have this problem.

Timoteo said:

Refer to TSB 05-12-6 as I suggested. Ford has a service kit that includes all effected bearings, seals and the gear set. They also include a sticker to refer the heavier gear oil that replaces the original 75W-90 with 75W-140 QL.

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I had mine replaced under limited warranty when I bought mine used. I haven't had any issues since. Get it taken care of soon though. I have heard that if you don't have it fixed, you can grenade the rear diff.

oh, that howl is back

yup. Had the rear end diff overhauled with "kit" 14,000 miles ago (12mos) and now it is back. Actually was back about 5,000 miles after the service but I didn't have time to take back to dealership. It has not gotten louder, it occures only when cruising at 30-45mph then goes away with deceleration or acceleration. Spoke with service advisor at a different dealership who quoted me about $1200 to service it; he did state that there isn't major danger in just leaving it alone. Noise level may increase, and that's about it. However, this pertains to the rear end diff. If the noise is from the hub assembly, it would be more affordable and may have more serious consequences if left alone.

Our '02 has had the rear diff replaced twice and rebuilt once. Since the last rebuild its been silent.

My '00 has developed it now. They've spent to much time in the garage together.

Mine will go in this Summer to have it looked at and hopefully replaced.

Todd

IAmTodd said:

Our '02 has had the rear diff replaced twice and rebuilt once. Since the last rebuild its been silent.

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What's the difference in cost between replaced and rebuilt for the '02 rear differential? What kind of warranty did they give for each?

Thanks!

Ours was done under the extended warranty so there was no cost.

As far as a warranty on the part now that its our of warranty, I'd have to ask my parents as its their vehicle.

http://www.explorerforum.com/forums/showthread.php?t=157872
http://www.explorerforum.com/forums/showthread.php?t=138420

My 2002 has 86K and a howl that almost drowns out the radio. Do I have any prayer of getting Ford to step up to the plate? What's the powertrain warranty on these *******s?

Sensing a trend...

I bought my 03 XLS on Valentine's day. It had a howling sound when decelerating with my foot off the gas.
Took it back to CarMax... the transfer case has to be replaced.

38K miles.

What else can I look forward to?

Mine was doing the chatter when I made slow turns but I had the rear diff serviced and it stopped.

Have read that the supplyer of the rear end, used worn equip to make the rear end's. The ring and pinion gears were not seated correctly, along with the non steal housing, alowing for heat related flex, and the miss alignment of the ring and pinion gear unit. If a unit is rebuilt, the part's must be pressed in all the way. Some places use care,( result, no return of noise) and some just get the job done,( result, the noise could, will come back). It is hard to say who is better at the rebuild. If 1 has the noise, and the warrenty, take the time and get the paper trail started, with the fix. In the long run, you will be happy, and able to enjoy the ride. Just my 2 cent's. P.S. Me- No money + no warrenty = Drive when I need to with radio up loud.

I have a 2002 XLT 4x4. I had the same symptoms. Turned out to be BOTH rear wheel bearings.

I've had this problem too. I got it "fixed" twice under warranty. My understanding is that there is a misalignment issue, but the work that they did was to replace the gears, which works great for about 10-15K miles. Unless they deal with the part of the problem that is causing the gears to go out of alignment, it will never be fixed. There is no way that I will pay $1,200 for half @$$ repair. I think the only thing that would work is to go for an aftermarket rearend with a different housing. If I decide to fight it I could probably get them to replace it under warranty since their warranty repairs did not really work, but it would mean escalations to Ford Corporate, and lots of time. For now I'm listening to the noise and wishing that I had purchased a 4Runner. I think this is the last Ford I will buy, primarily due to this issue. I love the size and functionality of the vehicle, but the quality is just not there.

Your description fits exactly the problem I had with my '03. I bought the car new and after a few thousand miles I noticed a whine in the rear..same as you described. I brought it to my dealer and at first told me they couldn't hear it. I waited another thousand miles. the noise was a little more noticeable. They replaced the rear end chuck. All was fine for a short while and then the noise started to return. To shorten this story...after 7 times to the dealer over a period of 5 years and 50k miles, they got it right. they replaced the ring and pinion gears and the whine is finally gone.
Jake T.

I've been living with the "howl" for years, and I'm now at about 60K miles. Last night I changed the differential fluid and put in Redline 75-145NS fluid with friction reducer. I know that the dealer put the 75 -145 synthetic in my car because they updated the sticker, but I don't know if they used the friction reducer, and I still had the howl after they worked on it last time. I drove it after changing the fluid last night and the howl is gone! Hopefully it is not temporary. I will be thrilled if this solved the problem.

my explorer has 120k, 2003 xlt 4wd w/out lsd..... been living with that damn whinning since aboout 35k...didnt pay much attention to it , but it got louder after 65k.. Same symptoms, starts at 55mph, get louder and stops after 65mph... i've read a ton of articles about changing rear end fluid and other remedies. spoke to a ford tech,he said he has 200k on his explorer and has never changed the fluid, "why bother" . Thankfully i had to change the hubs and bearings all the way around , and this forum was dead on with the how to's.. but i've decided to keep trucking with the whine. And lets not forget the serpentine belt noise that starts after 20k miles after being replaced. The balancer doesnt look warped but i read a few threads that it might be the culprit. ford did change the tensioner , once, claiming that was the problem- the thread also stated not to believe that was the problem , and the thread was dead on. Dmac156, let me know if it works!