02 Ford Explorer XLS 4X4 87k Rear End Noise

[tkline2908]

Hi Everybody

I have a 02 Ford Explorer :exp: XLS 4X4 with 87K on it. Recently I have noticed a noise coming from the rear end. I can hear the noise from about 15mph and up its consistent with the speed of the vehicle. I can hear the noise with windows up radio off and the climate control fan on 2nd setting. This happens all the time and is not intermittent, I can coast, brake, accelerate and corner the sound is always consistent with my speed. Its sounds like a tire, maybe a snow tire, but I have had my tires checked and they are fine.

I had one rear bearing on the right side replaced and installed a new tire and the noise is still there unchanged. I know I will need to change the left side wheel bearing at some time, but right now I would like advise on what I should be checking and inspecting to try and diagnose this problem my self.

Thanks in advance for all your help.

 

[imp]

Noise From the Rear

Gear noise usually resembles a whine, like a hum, which often is present only when the vehicle is under load, like pulling forward at speed. Such noise often is less, or gone, when coasting.

Axle bearings rarely produce a humming sound, but rather a lower-pitched sound, since the axles turn much slower than the driveshaft (pinion gear). A failing axle bearing may produce a sound resembling a constant rattle or clunking; these sounds usually are not changed by the vehicle pulling hard or coasting.

Locating the source of noise can be made easier by placing the vehicle on jack stands or a lift, with the wheels free to turn, and using a stethoscope to listen to internal sounds emanating from the differential carrier, axle ends, and so on. imp

 

[tkline2908]

Hi Thanks for the Quick Response to my Problem

I have heard about this kind of diagnostic technique. I guess that should be my next course of action. I don't think its coming from the differential because the noise is consistent with my speed, it sounds like I have a snow tire or tire noise of some kind. The noise is there and constant under all driving conditions even when coasting in neutral. I remember when one of the front wheel bearings went bad, it was all of a sudden and very noticeable and that sounded like loud snow tire.

Anybody else have any advise or had this experience with this problem.

 

[xlt03]

It could also be a pinion bearing. The infamous whine is a ring and pinion problem. Start with your other axle bearing first, it's the least expensive. If it's till there I would look at pinion bearing.

 

[thepotroast]

I had one rear bearing on the right side replaced and installed a new tire and the noise is still there unchanged. I know I will need to change the left side wheel bearing at some time, but right now I would like advise on what I should be checking and inspecting to try and diagnose this problem my self.

The left bearing

 

[piperRonnie]

I have the same noise and operating condition as you described.
Been there for the last ten months. I have not changed/repalced anything.
Noise is annoying but so far nothing bad has happened.

 

[imp]

Ignoring It.........

I have the same noise and operating condition as you described.
Been there for the last ten months. I have not changed/repalced anything.
Noise is annoying but so far nothing bad has happened.

Regarding noise caused by pinion or ring gear bearings: A failing pinion bearing will not last a long time, ring gear (differential side bearings) will grumble much longer before giving out, but in EITHER event, failure of the bearings supporting the gears results in a HORRENDOUS mess, like, destroyed gears, possibly cracked or broken housing, and a super-expensive and inconveniencing experience........imp

 

[tkline2908]

Hi Everybody

I am very glad to see some good advise in response to my problem.

Pinion gear bearing, that makes sense, it is rotating at the same speed as the rear wheels and would probably make a constant noise under a load or coasting. Is that a difficult job? can I do it in my garage over the weekend? or will it require special tools and a 20 ton press?

 

[imp]

Important note:

Hi Everybody

I am very glad to see some good advise in response to my problem.

Pinion gear bearing, that makes sense, it is rotating at the same speed as the rear wheels and would probably make a constant noise under a load or coasting. Is that a difficult job? can I do it in my garage over the weekend? or will it require special tools and a 20 ton press?

The pinion rotates MUCH faster than the wheels: 3.73 times faster, if the gear ratio is 3.73. For that reason, failing pinion bearing(s) pose a more immediate concern than axle bearings.

Replacing pinion bearings is tricky for the novice. They establish the tooth contact pattern of the gears, and since bearing manufacturing tolerances are wider than the necessary gear set-up requirements, shims are used beneath the bearings to establish correct gear tooth contact. Pinion bearings are a tight press-fit on the pinion shaft itself. These facts coupled with the need to also establish proper bearing PRELOAD on them, as well as their critical location, make this a non-routine job not for the novice. Many "mechanics" have been known to screw-up a pinion bearing job, let alone the do-it-yourselfer. Sorry. However, it is STILL not yet known what exactly is causing the noise. imp

 

[tkline2908]

imp that's good news

My noise appears to match the speed of my wheels not 3.73 times faster. My noise reminds me of the sound that a snow tire might make. Maybe I changed the wrong bearing first (left side instead of right) It sounds like I should focus on replacing the other rear wheel bearing so both are new and diagnose from there.

How about this? My Differential gear lube has never been changed, I have 87k on the truck and I understand it takes a 75/140 synthetic type lube. Would changing the Diff lube make a difference? or are all of you going to recommend I should change it anyway because its over due. LOL

 

[xlt03]

Agreed, do other bearing and take it out of the equation.
And yes on the fluid change, don't forget the friction modifier. Never mind what the synthetic gear fluid bottle says.

 

[tkline2908]

Hey wlt03

I have heard of the friction modifier from my repair manual where can I get it? Is it available at car parts stores or from the dealer? I have researched Mobil One Synthetic Gear lube LS 75w-140 and the Mobile One website says it includes a friction modifier. So do I need to add fords friction modifier?

Here is some info from the Mobil One website

Mobil 1 Synthetic Gear Lube 75W-140 LS contains special friction modifiers designed for limited slip-type differentials. In most applications, the addition of special LS (limited slip) additives is not required. For axles requiring the highest level of limited-slip performance, OEM specific LS additives can be added to this fluid.

 

[xlt03]

Mobil 1 Synthetic Gear Lube 75W-140 LS contains special friction modifiers designed for limited slip-type differentials. In most applications, the addition of special LS (limited slip) additives is not required. For axles requiring the highest level of limited-slip performance, OEM specific LS additives can be added to this fluid.
I went with the friction modifier from Ford. Wasn't that much. You can also get from AutoZone, Kragen/O'Reily etc. it comes in a larger quantity. The Ford packaging was the right amount and I don't have any leftovers. This stuff STINKS, even the outside of the bottle smells.

 

[MP301]

Well, the OP never returned to post how the situation was corrected and I have almost the exact same issue.

The noise is constant with the speed of the vehicle. It sounds like cupped or aggressive offroad/snow tires. Tires being the problem has been eliminated because the noise started a bit before I was to replace the tires and it has not changed with the new tires I put on a couple of days ago...

The only difference with my situation from the OPs is that my noise will completely go away when turning to the right (shifting the vehicles weight off of the right axle).

Would this be a strong indicator that my right wheel bearing is the culprit? If so, is this an easy job for a novice?

Thanks for any help!

 

[BigRondo]

Well, the OP never returned to post how the situation was corrected and I have almost the exact same issue.

The noise is constant with the speed of the vehicle. It sounds like cupped or aggressive offroad/snow tires. Tires being the problem has been eliminated because the noise started a bit before I was to replace the tires and it has not changed with the new tires I put on a couple of days ago...

The only difference with my situation from the OPs is that my noise will completely go away when turning to the right (shifting the vehicles weight off of the right axle).

Would this be a strong indicator that my right wheel bearing is the culprit? If so, is this an easy job for a novice?

Thanks for any help!

Welcome to the forum!!

You could do a search for "rear end noise".

Here is a great thread for changing the front wheel bearings.

Here is a great thread for changing the rear wheel bearings.

Good luck with the fix! :biggthump

 

[MP301]

Welcome to the forum!!

You could do a search for "rear end noise".

Here is a great thread for changing the front wheel bearings.

Here is a great thread for changing the rear wheel bearings.

Good luck with the fix! :biggthump

Thanks for the welcome! Yeah, thats how I found this thread...I ran out of time so I didnt keep looking...this guys problem is the same as mine.

I also found an awsome thread on changing the rear bearing complete with pics that was great as well...

 

[BigRondo]

Thanks for the welcome! Yeah, thats how I found this thread...I ran out of time so I didnt keep looking...this guys problem is the same as mine.

I also found an awsome thread on changing the rear bearing complete with pics that was great as well...

You're welcome. You can find pretty much anything on here that you need.