2002 Ford Explorer V8 hummmm noise from rear differential

[popalzai]

I bought this truck used in nov 2009 at 86000 miles and now its 96000 miles...and just recently i started hearing a humm sound from rear differential(just like the sound of airoplane) which starts at 20 miles and goes uptill 60miles...oil from rear differential seal was also leaking which was fixed when i got the seal replaced...but the sound is still there...what is the cheap solution for this...and what dangers are there if i keep on driving like this with the sound?

 

[xlt03]

Assuming that you have eliminated the rear bearings as suspect, I would say that the main bearing of the pinion may be bad. If that is the case I would have the rear end rebuilt and replace the ring and pinion as long as it's apart. You can replace it with the racing version of ring and pinion. What would rebuilding accomplish? Seal leak, ring & pinion whine which are annoyance problems on seemingly all Exploders. But double check the hub bearings first.

 

[EasyRhino]

Rear differential noise is a common and well-documented problem with these Explorers.

For most, the worst result is noise only, although some have had their differentials grenade on them (not common).

Mine, bought new in May 2002, has done this from essentially new. Now at 8+ years and 105K miles, is no worse and no better.

Make sure that the lubricant has been updated to the 75W-140 synthetic with the friction modifier - that's the first step.

If it gets too bad, there are kits to rebuild it with new pinion and carrier bearings (the source of the noise).

Do a detailed search here, lots of threads on this malady.

Me, I'm just living with it until it demands more attention.

 

[CALDWELL]

^^^^^^^^^ what he said... the " whine " is a common problem on x's

 

[NJExplorerFan]

If you purchase a Ford ESP, does it cover and fix this problem?

 

[xlt03]

ESP covers drive train. Read the plan that you bought or going to buy (ie., premium care, extra care, etc.)

 

[bjboertje]

i was wondering the same thing, the ESP i am looking at says this:
• Axle Shafts
• Bearings (Front
and Rear)
• Drive Axle Housing
and Front Axle
Housing for 4x4
(Including All
Internal Parts)
• Driveshaft
• Retainers
• Seals and Gaskets
• Universal
and Constant
Velocity Joints

would this be covered in the drive axle housing part?

 

[xlt03]

Ford ESP Click on the plan that you want. Also note that on the Rear Wheel Drive tab it also says including internal parts, to me it should cover ring and pinion also.

 

[imp]

• Drive Axle Housing......Front Axle Housing for 4x4 ....(Including All Internal Parts)

would this be covered in the drive axle housing part?

Yes. However, some gear-related hum will be waived-off by the repair group as "normal and acceptable".

Actually, the type of gearing present in these axles is supposed to be silent in operation, due to it's design: the gear teeth do not slide over one-another, but rather experience rolling friction for all but the most heavily-loaded duty-cycle. They are known as "hypoid gears".

Knowing this, I am personally suspicious of claims that all Explorer differentials produce noise. The possibility exists that noise is more common than in the past, due to the less-rigid construction of these housings: they are aluminum instead of cast-steel, as in the past. Gear noise is produced when deflections are present between the gears' supporting members. Deflections (in excess of normal) occur when bearings are failing, and, possibly, due to the less-rigid aluminum housings. If the latter cause is prevalent, then yes, many will hum to the occupants. imp

Edit: It may be possible, given a "singing" gearset having good, properly set-up bearings, for a guy expert in assembling hypoid gearsets to "lead" the housing's deflection to some extent by altering the tooth contact pattern slightly toward the "heel" end of the ring gear's teeth.

 

[jakedrew]

my 04 did this at 55k miles.

What I noticed is when the truck was warmed up ( like 10 miles of driving) I give it gas, let off, give it a little bit of gas and the humming noise would come and go depending if I gave it gas. Started to make noise at 50mph ish.

Good luck, My ford extended warrenty covered mine.

 

[eirechef]

Same issue with mine. I am trying to eliminate the rear bearings as the culprit. If the whine continues through exceleration and goes away when you take your foot off the gas I would suspect the diff. otherwise change the wheel bearings. Mine has 165000 so it wouldn't hurt.

 

[jreid]

humming and binding in the explorer

my 2002 explorer 4wd 4 liter v8... does all of the above, with the additional feel that its stuck in 4 wheel drive, and has been since about 40,000 miles (80 k now). When i accelerate in a corner or going up an incline while turning, i hear and feel a binding. I notice it more on right turns than left turns. In town, i go around a corner idling, then accelerate when the car is straight in order to avoid the horrible binding sound. At 35,000 i took the car to the local ford dealer, to investigate the strange humming coming from the rear. It was louder when i left the dealership 3 days and 1200 dollars later. I dont go back there. I still dont know what the sound is, and i dont have the funding to do exploratory with the compromised skill level that I often see in this area. I have attempted to get estimates of a fix of the noise, ASSuming that noise is almost never a good thing. But i get only dollar estimates from people who cant really say what the noise is, but 'we'll fix it'. I would love to be able to tow my pop up camper but i fear that i would be stranded someplace. The car came with a 2in x 2in hitch and towing package.

 

[imp]

ESP's?

Regarding this ESP business: I take it these are a form of "insurance", so to speak. If so, please be aware that if one goes to virtually any big city downtown area, those skyscrapers will be heralded on top by big signs saying Prudential, New York Life, Kemper, etc. This suggests there is a mountain of money to be made in the insurance game (only as the insuror, however.

Sears, for example, sells "MAs", Maintenance Agreements. The sales associates really push those MAs; know why? Because many stores pay the associates a couple bucks bonus for every one they sell! A Store Manager once confided in me that Sears makes more profit selling MAs than that garnered by the sale of the appliance.

So, I'm saying that I am "down" on ESPs, MAs, etc. Doesn't it only seem right that if one lays down 20 or 30 "big ones" for a vehicle, that cost should include reasonable assurance that the damn product was made to be trouble-free for a good long time?

If I have opened a "can of worms" with this, don't be bashful! Speak up and put me in my place! imp (anti-Insurance guy)

 

[RickM]

Same issue with mine. I am trying to eliminate the rear bearings as the culprit. If the whine continues through acceleration and goes away when you take your foot off the gas I would suspect the diff.

Correct, the rear diff noise presents itself while under load.

 

[Black92LX]

Had the same problem.
I swapped my fluid, when I drained mine it was kind of milky making me believe water had gotten in somehow. Swapped out the rear diff fluid and used Amsoil Severe Duty Gear Oil and Ford Friction Modifier. Noise went away and have had zero problems in 25,000 miles.
If you had a leak in the diff moisture or water could have got mixed in

 

[pufahl]

Differential hummm

I have 1999 Mercury Mountaineer with 65k miles and the differential is making a humming noise. The rear end is a 8.8 3.78 ratio based on the axel tag. I've read everything and first step was to replace the fluid with new 75W-140 full synthetic with friction modifier and the noise is still there. I notice there is about 1/8 - 1/4 inch slack in the differential when I turn it and reverse the turn. I suspect this is the cause of the humming. I'm considering a rebuild kit for the differential and new wheel bearings while I have it apart. I've learned there is a TSB for this problem but it looks like it has already been done to this axle because it has the new oil tag affixed. Before I do I would like to some advice from the experts. Does anyone have a supplier that sells the rebuild kits and wheel bearings?

 

[imp]

I have 1999 Mercury Mountaineer with 65k miles and the differential is making a humming noise. The rear end is a 8.8 3.78 ratio based on the axel tag. I've read everything and first step was to replace the fluid with new 75W-140 full synthetic with friction modifier and the noise is still there. I notice there is about 1/8 - 1/4 inch slack in the differential when I turn it and reverse the turn. I suspect this is the cause of the humming. I'm considering a rebuild kit for the differential and new wheel bearings while I have it apart. I've learned there is a TSB for this problem but it looks like it has already been done to this axle because it has the new oil tag affixed. Before I do I would like to some advice from the experts. Does anyone have a supplier that sells the rebuild kits and wheel bearings?

If the main gears, the ring and pinion, are scored or burned, no repair kit will eliminate the noise. The best approach is to remove the differential cover plate, and inspect the gear tooth mating surfaces first. If they are shiny and bright after you wipe off the film of oil, they are likely OK.

What are you turning when experiencing the 1/4 inch slack, the driveshaft? The 1/4 inch being gauged at the outside diameter of the shaft? If both wheels are held stationary, like on the ground, that amount of slack would not be excessive. imp