Wheel bearing noise vs differential noise?

[The motor guy]

Im getting a humming sound that I notice even as slow as 10-25mph. Something is either out of balance like these old tires I have. You still notice it coasting to a stop even. I want to say its my Moog wheel bearing i replaced on the front drivers side, but its really hard to tell if its coming from the front or the back.it was quiet for a while. Then after like 30k .miles its getting noisy again. Funny how the oem wheel bearings can go 250k with no issues

 

[johnmyster]

Wheel bearing is generally a low pitched groan that gets louder but does not change pitch with acceleration. It will also get louder with hard cornering as load on the wheel bearing (outside of turn) increases.

Tire cupping is the "whomp-whomp-whomp" at low speed that increases frequency with speed, can be hard to locate, and turns into a solid "WHAAAAAAA" once you're going fast enough.

If it's a front wheel drive car with excessive rear negative camber, start by feeling for cupping on the rear, notably inside edges.

 

[Number_35]

(In my experience) diff noise is a whine under constant speed that disappears as soon as you let off the gas.

A wheel bearing on the way out often makes "airplane noise". It can sound very similar to a bad tire. (Last winter I was sure I had a wheel bearing failing. It made it through the winter, and the noise went away as soon as I did the seasonal tire change.) As @johnmyster said, you can test for a noisy wheel bearing by seeing if the noise varies when the car turns. Driving a slalom or Figure-8 pattern in a big parking lot is a good way to test. If the noise is otherwise constant (though proportional to speed) when going straight, but goes away when you turn L, it's the R wheel bearing (and vice versa).

 

[The motor guy]

Guess ill put new tires on the back and see how it sounds since they're dye for replacement now. They did have a shimmy when they were up front. I hope putting those tires in the rear didnt hurt my rear differential.

 

[xmanjeff]

whats the vehicle ?

 

[The motor guy]

whats the vehicle ?

My 2007.5 dodge ram 2500 2wd diesel

 

[HemiBenny]

You seem to be having one problem after another with your trucks.

 

[The motor guy]

You seem to be having one problem after another with your trucks.

I do have some flat spots on my back tires, so im hoping that's all it is. Hope the rear diff isnt going out. I haven't heard of anyone having issues with an 11.5aam axle. Even at 400k

 

[The motor guy]

I can see it wearing out axle bearings, but I dont know if an unbalanced choppy tire would effect the actual rear differential. Wheel bearings are cheap compared to a whole rear diff.

 

[The motor guy]

(In my experience) diff noise is a whine under constant speed that disappears as soon as you let off the gas.

A wheel bearing on the way out often makes "airplane noise". It can sound very similar to a bad tire. (Last winter I was sure I had a wheel bearing failing. It made it through the winter, and the noise went away as soon as I did the seasonal tire change.) As @johnmyster said, you can test for a noisy wheel bearing by seeing if the noise varies when the car turns. Driving a slalom or Figure-8 pattern in a big parking lot is a good way to test. If the noise is otherwise constant (though proportional to speed) when going straight, but goes away when you turn L, it's the R wheel bearing (and vice versa).

I think its just the back two tires. Gave it a good listen on the drive home at 60mph letting on and off the throttle. I hear a faint quiet hum which I believe is the rear diff. Its always made a slight hum since day one, but 90 percent of the rest of the noise seems to be either rear tires or a rear wheel rear bearing. I think its just my tires. Its hard to seperate the different noises lol

 

[Number_35]

I think its just the back two tires. Gave it a good listen on the drive home at 60mph letting on and off the throttle. I hear a faint quiet hum which I believe is the rear diff. Its always made a slight hum since day one, but 90 percent of the rest of the noise seems to be either rear tires or a rear wheel rear bearing. I think its just my tires. Its hard to seperate the different noises lol

Does it seem to be one side more than the other?

You could swap the rear tires side-to-side to see whether the noise moves with tire.

You could also move the rear tires to the front and see whether the noise moves to the front.

 

[The motor guy]

Does it seem to be one side more than the other?

You could swap the rear tires side-to-side to see whether the noise moves with tire.

You could also move the rear tires to the front and see whether the noise moves to the front.

No not really. Pretty sure both lift and right had flat spots. They made the steering wheel shake when they were on the front. I had a wheel bearing go bad on the front that made the abs light come on, so I locked up the tires a couple tires since the abs is disabled when the light is one. I guess the flat spots never really do go away by rotating to the back. Really the only thing to do first is get new tires

 

[Tundragod]

(In my experience) diff noise is a whine under constant speed that disappears as soon as you let off the gas.

A wheel bearing on the way out often makes "airplane noise". It can sound very similar to a bad tire. (Last winter I was sure I had a wheel bearing failing. It made it through the winter, and the noise went away as soon as I did the seasonal tire change.) As @johnmyster said, you can test for a noisy wheel bearing by seeing if the noise varies when the car turns. Driving a slalom or Figure-8 pattern in a big parking lot is a good way to test. If the noise is otherwise constant (though proportional to speed) when going straight, but goes away when you turn L, it's the R wheel bearing (and vice versa).

I agree so some but not all of these with my latest experience on a 2012 Highlander rear wheel bearings AWD.
Back on 1/9/25, I replaced tires from Michelin LTX, 4-5/32 to Vredestein Pinza. I thought it was the tires. It got louder "airplane noise" as the year progresses. I ignored it as my daughter was driving it. Winter comes so Blizzak DM-V2 went on. Noise still there and sounded somewhat louder (35 - 70mph). I tried to check the wheel bearings with tires off, couldn't tell. So, I order 2 cheap Amazon's PAROD 512284 Rear AWD Wheel Bearing & Hub Assembly. I figured, $90 expense/test (first time replacing bearing) is just a learning experience if the cheap parts are bad. 1/08/26, I took the old bearings out. Tried to spin and compared to the new bearings, I couldn't tell if the old ones were bad. I put the new ones on. The noise is gone......ecstatics. Will see how these cheap bearings last. The Parod bearings feel like they are built well.
Cost 2x~ OEM - $735.25, Timken - $311.10, Parod - $90.80

 

[Number_35]

I agree so some but not all of these with my latest experience on a 2012 Highlander rear wheel bearings AWD.
Back on 1/9/25, I replaced tires from Michelin LTX, 4-5/32 to Vredestein Pinza. I thought it was the tires. It got louder "airplane noise" as the year progresses. I ignored it as my daughter was driving it. Winter comes so Blizzak DM-V2 went on. Noise still there and sounded somewhat louder (35 - 70mph). I tried to check the wheel bearings with tires off, couldn't tell. So, I order 2 cheap Amazon's PAROD 512284 Rear AWD Wheel Bearing & Hub Assembly. I figured, $90 expense/test (first time replacing bearing) is just a learning experience if the cheap parts are bad. 1/08/26, I took the old bearings out. Tried to spin and compared to the new bearings, I couldn't tell if the old ones were bad. I put the new ones on. The noise is gone......ecstatics. Will see how these cheap bearings last. The Parod bearings feel like they are built well.
Cost 2x~ OEM - $735.25, Timken - $311.10, Parod - $90.80

If it's not too bad a job and you're doing it yourself, perhaps the cheap bearings make sense.

The ones I've done in recent years have been on FWD vehicles (Mazda and Kia), and are a lot of work. Therefore, I've used the best parts I could find.

 

[crashz]

Unlikely its the rear wheel bearings, but give the oil in the diff a check and feel for play in the pinion and gear lash if you can do it safely (flat ground, wheels chocked, in neutral, engine off). If you have flat spots on the tires that's probably it.

Are the 2wd trucks equipped with unit bearings in the front? I had a very light sound, from somewhere and tracked it down to the right front wheel bearing in my F250. It felt fine until I got the rotor off and when spinning had a slight notchy-ness to it.

 

[Ursatdx]

From another site:

2007 Dodge Ram 2500 2WD Diesel (6.7L) commonly experiences rear differential issues, specifically with the American Axle (AAM) units. Key problems include loose ring gear bolts that can destroy the housing, worn limited-slip clutches, and pinion seal leaks leading to low fluid. Symptoms include whining/whirring noises, vibrations, and metal debris in the oil.