Humming Noise At Rear of Vehicle

[SUV_RIDER]

I just may give that a shot. I'm tempted to try it myself after reviewing the "How-To" procedures in the Haynes manual. From what i learn thus far, this doesn't seem to complicated. My main concern is how to put it back in. Suppose you need some sort of hand pump ha?

Another tip, I found if i show up at the quick lube joint, with my own fluid, Mobil1, they only charge me $15 to siphon it out and refill with my stuff, $30 for both. If you have two do both and fill with Full Synth 75-140w F/R . I use Mobil1 also amsoil or royal purple are good too. They say in the book to use 80/90w for the fronts but a couple of rebuilders said the factory only does that to save money, and when they rebuild them they put in the 75w-140. If you have LSD there is a special bottle (friction modifier) that needs to be added.

 

[jrford]

They use shop air and a special vacuum pump and they only do it through the fill hole.
If you do it yourself, biggest thing is get the fill plug off first. . .then the drain plug. A lot of diffs only have a fill hole anyways. For the Ex they give you a drain plug in the rear but not the front.

 

[SUV_RIDER]

Got it! Thanks very much for that info!

They use shop air and a special vacuum pump and they only do it through the fill hole.
If you do it yourself, biggest thing is get the fill plug off first. . .then the drain plug. A lot of diffs only have a fill hole anyways. For the Ex they give you a drain plug in the rear but not the front.

 

[gshep12]

Ford was using I believe at start of the 3rd gen explorers 75w 90w for the rear diff. That has changed as far as my understanding goes. The weight has been increased to I believe 75w 140w. I have a 04 EXP Limited with the same symptom. I've been told outside this forum by 4 different people including my own brother, that it sounds like the Pinion bearing based on symptom. When there is a load on the drivetrain (acceleration) the howling is there, lift foot off gas (dacceleration) and the howling or humming goes away; you can check other Post in this forum. Ford has had many issues with this. Their fix is to change the whole pumpkin because it's more cost effective as opposed to pulling apart the rear diff and replacing gears, that's too time consuming and if you don't get it right you're pucked. I'm in preparation of dealing with this same issue as I post this reply. 4 new shock/struts and address diff noise. Wheel bearings to my understanding don't make the same noise when they go. You can check fluid level and fill if low; just maybe you'll be lucky and the problem goes away, I doubt it. Keep us all posted; good luck. Ford wants $1600 for the repair. Here in New Jersee they get $95 to $105 an hour for labor. The Pumpkin is $1200 and change. Your Front Diff fluid will probably be cleaner than the rear unless you use 4WD a lot. 4Wheel auto, high and low. I think it safe to assume most of us spend most time in auto mode. Rear diff does all the work?
*Sorry for reiterating what was already said. I didn't thoroughly read all post on this subject.*

 

[gshep12]

So how do i determine if i have "advanced trac" or not?

Possibly by VIN number. That's a wild guess on my part; call a dealership to inquire.

 

[SUV_RIDER]

Thanks for sharing that info! I think i will start with checking the fluid. if it continues, then i will take to a transmission shop for observation. FORD will be my last resort since they are sky high on service. Until then, i suppose i will just turn up my stereo system. Sometimes, i can still hear it with the stereo turned up. I think i'm going to get rid of mines in a few years and go with a GM Tahoe or just a 4X4 pickup truck. Who needs all this aggravation? Mine only has 68K miles on it. I can't believe i'm having this issue. I know two other guys with the same vehicle (2003 Explorer). They both had to replace their transmission. Both have less than 100K miles on them. Now, whats up with that? i just found out from one of them that there is not even a dipstick on these things to check the transmission fluid. I NEVER!

Ford was using I believe at start of the 3rd gen explorers 75w 90w for the rear diff. That has changed as far as my understanding goes. The weight has been increased to I believe 75w 140w. I have a 04 EXP Limited with the same symptom. I've been told outside this forum by 4 different people including my own brother, that it sounds like the Pinion bearing based on symptom. When there is a load on the drivetrain (acceleration) the howling is there, lift foot off gas (dacceleration) and the howling or humming goes away; you can check other Post in this forum. Ford has had many issues with this. Their fix is to change the whole pumpkin because it's more cost effective as opposed to pulling apart the rear diff and replacing gears, that's too time consuming and if you don't get it right you're pucked. I'm in preparation of dealing with this same issue as I post this reply. 4 new shock/struts and address diff noise. Wheel bearings to my understanding don't make the same noise when they go. You can check fluid level and fill if low; just maybe you'll be lucky and the problem goes away, I doubt it. Keep us all posted; good luck. Ford wants $1600 for the repair. Here in New Jersee they get $95 to $105 an hour for labor. The Pumpkin is $1200 and change. Your Front Diff fluid will probably be cleaner than the rear unless you use 4WD a lot. 4Wheel auto, high and low. I think it safe to assume most of us spend most time in auto mode. Rear diff does all the work?
*Sorry for reiterating what was already said. I didn't thoroughly read all post on this subject.*

 

[gshep12]

Thanks for sharing that info! I think i will start with checking the fluid. if it continues, then i will take to a transmission shop for observation. FORD will be my last resort since they are sky high on service. Until then, i suppose i will just turn up my stereo system. Sometimes, i can still hear it with the stereo turned up. I think i'm going to get rid of mines in a few years and go with a GM Tahoe or just a 4X4 pickup truck. Who needs all this aggravation? Mine only has 68K miles on it. I can't believe i'm having this issue. I know two other guys with the same vehicle (2003 Explorer). They both had to replace their transmission. Both have less than 100K miles on them. Now, whats up with that? i just found out from one of them that there is not even a dipstick on these things to check the transmission fluid. I NEVER!

Yeah they have a close system, if it were low on fluid as with the differential it would present itself under the vehicle or on the ground. So you have to assume that the fluids are full and you need repair, ride it to it goes. As for me I'm having mine repaired. I'm a strong believer than when I neglect to take action it usually come back to bite me where the sun doesn't shine. One thing leads to another/ The repair is a far sight cheaper than getting rid of the vehicle and having to make payment on something that you could potentially run into problems as well. Nothing in this world is perfect. You can always run but you can't hide. Good luck to ya!

 

[Port]

just a little 2 cents, but if the noise is on tip in throttle then it sounds like a ring and pinion. A pinion bearing will usually be pretty loud and will still be there some after letting off the throttle whereas the ring and pinion will go away. won't hurt anything really just gets annoying. and if it's advancetrac it'll say it on the back gate and u don't have a limited slip diff. Also 3.55 gearsets aren't limited slip either, just 3.73's. I added one to mine when i put axle seals in it. And to fill it in the vehicle is a pain in the butt. U should fill it at the ABS sensor located on top of the differential and u fill it till it comes out of the axle shafts not the drain plug! If you don't it won't be enough. It'll hold about 2-2 1/2 qts. I know this all sounds like a pain but it's about the only way. I use to fill them before i put them in. I'd rebuild them on the bench and had 2 plugs for the axle shaft holes so i'd fill them up, stick the diff in and pull the plugs and jam in the axles. Just watch the circlips, they sometimes catch when pulling out the axles and then it can get real bad! Mine has almost 140k on it and still rides and drives great.

 

[gshep12]

just a little 2 cents, but if the noise is on tip in throttle then it sounds like a ring and pinion. A pinion bearing will usually be pretty loud and will still be there some after letting off the throttle whereas the ring and pinion will go away. won't hurt anything really just gets annoying. and if it's advancetrac it'll say it on the back gate and u don't have a limited slip diff. Also 3.55 gearsets aren't limited slip either, just 3.73's. I added one to mine when i put axle seals in it. And to fill it in the vehicle is a pain in the butt. U should fill it at the ABS sensor located on top of the differential and u fill it till it comes out of the axle shafts not the drain plug! If you don't it won't be enough. It'll hold about 2-2 1/2 qts. I know this all sounds like a pain but it's about the only way. I use to fill them before i put them in. I'd rebuild them on the bench and had 2 plugs for the axle shaft holes so i'd fill them up, stick the diff in and pull the plugs and jam in the axles. Just watch the circlips, they sometimes catch when pulling out the axles and then it can get real bad! Mine has almost 140k on it and still rides and drives great.

Thanks for your insight; I meant to say ring and pinion, that's what I was told the symptom sounded like.

 

[F1EA]

I have the same whine, but cant really tell if its coming from the front or the rear. It sounds like its coming from the front... but im not too sure (mine is AWD '03 V6)

The noise is at its most at constant speed between 30-40 mph (under slight acceleration. Its not as bad when given hard throttle) and dissapears instantly when i lift off gas. When i re-apply gas it takes a little time to re-appear. On no gas its pretty silent at any speed.

What is likely to be the cause? the ring and pinion or the diff bearings? front or rear?

 

[dlvango]

I had humming that I thought was the rear differential at 52k. I have the ford ext. warranty so I brought it in. They replaced the rear axle bearings. Now it sounds like a new car.

 

[jakedrew]

I also had the rear end fixed at 50k miles. Same thing as others, give it a little gas and you can hear it, let off and it goes away.

 

[XCAMP]

I had humming that I thought was the rear differential at 52k. I have the ford ext. warranty so I brought it in. They replaced the rear axle bearings. Now it sounds like a new car.

Glad you found a fix, but this is different, if you hear the noise, let off the gas, and it goes away, and if you get back on the gas and it comes back, it's the rear pinion whine.

 

[zerokool]

I just took mine in to get the gears, pinion seal and bearing, and spider gears replaced. It cost me 1600 and it whined on the way home. So now mine is back in the shop. It's not anywhere near as loud as it was, but it's still there.

 

[XCAMP]

That stinks man. I took mine in for shaking at highway speed, spent $1200 on a drive shaft, axle, etc, and it still shakes, I live with the shaking and whining down the highway now, such a pain when you spend the cash and you don't get it fixed.

 

[J.Rovirosa]

Ford was using I believe at start of the 3rd gen explorers 75w 90w for the rear diff. That has changed as far as my understanding goes. The weight has been increased to I believe 75w 140w. I have a 04 EXP Limited with the same symptom. I've been told outside this forum by 4 different people including my own brother, that it sounds like the Pinion bearing based on symptom. When there is a load on the drivetrain (acceleration) the howling is there, lift foot off gas (dacceleration) and the howling or humming goes away; you can check other Post in this forum. Ford has had many issues with this. Their fix is to change the whole pumpkin because it's more cost effective as opposed to pulling apart the rear diff and replacing gears, that's too time consuming and if you don't get it right you're pucked. I'm in preparation of dealing with this same issue as I post this reply. 4 new shock/struts and address diff noise. Wheel bearings to my understanding don't make the same noise when they go. You can check fluid level and fill if low; just maybe you'll be lucky and the problem goes away, I doubt it. Keep us all posted; good luck. Ford wants $1600 for the repair. Here in New Jersee they get $95 to $105 an hour for labor. The Pumpkin is $1200 and change. Your Front Diff fluid will probably be cleaner than the rear unless you use 4WD a lot. 4Wheel auto, high and low. I think it safe to assume most of us spend most time in auto mode. Rear diff does all the work?
*Sorry for reiterating what was already said. I didn't thoroughly read all post on this subject.*

Similar whining/howling noise on our '03, dealer replaced the pumpkin under warranty.