Whining Sound @ 55-60mph+

[NJExplorerFan]

As a recent purchaser of my Explorer, I had a question regarding something I noticed the other day when driving on the highway. I heard a whining sound in the rear @ 55-60mph+. Doesn't sound like anything major, just a little annoying to hear if the radio is off. LOL... You can only hear it when you apply any slight throttle. Going down a hill at that speed it's completely silent. Comes on ONLY when you give it the slightest touch of the gas pedal.

Could this be the transmission? Gears? New fuel pump? I do have to give it a full tune-up still

 

[miker104]

Rear Differential. Try changing the differential oil to a 75W140 synthetic oil. Search on this forum for whine or noise and start reading.

Disregard the above comment. Yours doesn't make noise going downhill and is heard when you give it throttle. Bad differentials do the opposite.

Good luck

 

[jakedrew]

rear diff. same thing with my 04. give it a little gas and you can hear it howl, let off and it goes away at/ about 50 ish mph.. The truck has to be warmed up. When i left it at the dealer the first time overnight, they took it out in the morning and didnt hear anything( plus it was raining). I had to come back in and put about 10 miles on it till I could hear it.AND then the mechanic came for a ride in it and then heard it.



1100$ at ford it cost to replace the ring and pinion and add thicker fluid/ 75w140. ( well 100$ for my extended warrenty deductable )

good luck

Good luck.

 

[NJExplorerFan]

So what would changing to 75W140 synthetic oil do? Make the sound go away completely? Is that a temporary or permanent fix?

If any parts needs to be replaced, which ones? Approx. cost of a job like this?

 

[miker104]

There was a Ford TSB on changing the rear diff fluid to the 75W140 spec. It was meant to quiet the noise from the differential. All that is needed is some of the fluid and if you have a Limited Slip (LS) differential you need to add the friction modifier. I think there is a thread on here about changing the oil. I can't seem to find the TSB, I thought I had a copy.

Its a relatively easy fix and may just quiet your Ex down enough to give you piece of mind.

If its the ring and pinion there is a TSB to fix that too but its about $1100-$1600 at Ford to have done. One member on here sells rebuilt diffs for about $800 if memory serves.

Do you have the Independent Rear Suspension (IRS) or do you have the solid axle (2WD)?

 

[NJExplorerFan]

There was a Ford TSB on changing the rear diff fluid to the 75W140 spec. It was meant to quiet the noise from the differential. All that is needed is some of the fluid and if you have a Limited Slip (LS) differential you need to add the friction modifier. I think there is a thread on here about changing the oil. I can't seem to find the TSB, I thought I had a copy.

Its a relatively easy fix and may just quiet your Ex down enough to give you piece of mind.

If its the ring and pinion there is a TSB to fix that too but its about $1100-$1600 at Ford to have done. One member on here sells rebuilt diffs for about $800 if memory serves.

Do you have the Independent Rear Suspension (IRS) or do you have the solid axle (2WD)?

Sorry, I'm fairly new on here so can you clarify what a "TSB" is? Also, I have the IRS. Also, is there any harm in driving with the whine until I get the money to fix it?

 

[miker104]

TSB=Technical Service Bulletin. Is a notice to Ford dealers that if a customer comes in with this complaint, here is how to fix it.

Here is a link to a how to thread.

http://www.explorerforum.com/forums/showthread.php?t=213749&highlight=differential+fluid

I would do the fluid change unless it has been done before, its relatively cheap and may save you more money in the long run. Many here have let the rear end whine for long time. The worse possible outcome is the rear diff may grenade (blow up into little bits) but as long as the fluid level is kept at the correct level I doubt that would be probable.

The rear axle seals are also known to leak that can cause the fluid level to drop so keep an eye on it.

Changing my rear diff fluid is on my to do list but I think the rear wheel bearings will probably get done first and may get the axle seals and fluid change done at same time.

 

[RickM]

Do you have the Independent Rear Suspension (IRS) or do you have the solid axle (2WD)?

Appears he has the IRS. 2003 XLT V8

 

[XCAMP]

It's the rear pinion whine that many of us have, changing the fluid only seems to quiet it down, or change at what speed it happens, it won't solve it, trust me I have tried different variations of fluid, more or less friction modifier, it won't solve it.

So I just ignore it like many others on here.

I have read about people who spent the $1200 to get it fixed and it comes back a few thousand miles later. I have not heard of anybody experiencing a complete failure due to this, but please correct me if I am wrong.

 

[NJExplorerFan]

I did contact my local Ford dealer this morning and they mentioned about $100 for the new fluid and $100 labor. They said it takes about 1 hour. I'm gonna get estimates from local shops as well to see what they charge. For just changing fluids, $200 seems quite high.

Does that seem right?

 

[XCAMP]

That's unfortunately about right at most shops, although it is a rip off.... you can do it yourself very easily if you have a few things on hand. If you don't, by the time you buy the right socket to pull the plug, and get yourself a vacuum pump or something to get the fluid in, you may as well just take it in. The synthetic fluid is about $20 a bottle and you need like 1.5 bottles. The friction modifier is a few bucks, so at most, you are talking $50 in fluids if you do it yourself.

 

[miker104]

Some of the quick lube places offer differential fluid service. Some have had major problems at some quick lube places. Perhaps find a local garage with a good reputation, ask your friends/neighbors/co-workers where they take their cars for service and what they think of them? Most independent shops charge less that dealer labor rates, but a few of them are not trustworthy, the challenge is to find the right one without getting ripped off.

As most have said it may not make your issue go away, and is not likely to cause major grief but you can always turn up the radio!

 

[NJExplorerFan]

I haven't looked under there yet, but is there a plug or does the whole cover have to come off?

 

[XCAMP]

It's a plug, you just pull the plug with a very large 3/4 drive socket extension. The fluid won't just come out, you have to siphon it out.

 

[Extremistno9]

Try this link as well. I have done the fluid change to eliminate the rear shutter in the diff. My diff is quiter but still has some howel to it. I think this summer I will replace the fluid one more time, since I did not do the flush that the dealer and shop recommended.

http://www.explorerforum.com/forums/showthread.php?t=248723