So I started hearing a noticeable hum over a year ago, and it seems to be coming from the rear. Can't discern which side, or if it's maybe even both. Needed new set of tires about 5,000 (maybe closer to 10,000) miles after I first remember noticing the noise. Noise was unchanged with new tires, so I can't imagine it's tire related. I now have about 20,000 miles on these tires. I'm sure the noise is louder as time and miles go by, but the change is gradual enough that I'm immune to noticing the difference. All I know is it's definitely concerning. It's loud enough that at 60+ mph, conversation requires raising your voice. I remember noticing how I could have a conversation at a normal volume when I first got this car, moving up from my 2003 Sentra SE-R. (I'd love to hop in someone else's G35 Coupe and hear the difference..)

I've been suspecting a wheel bearing, but there's no evidence of that other than the noise. The wheels have no play when trying to rock them around with the car off the ground. I replaced rotors and pads earlier this year and went from corner to corner, spinning the hubs, and I can't say there was even any difference in the feel, aside from the rears having a bit more resistance due to being connected through the differential.

I have a 30+mile one-way commute, and I took my wheels off immediately after getting home one day last week. I used an IR thermometer to check every point I could think of around the rear hubs, as well as the fronts, and didn't get any readings above about 120-130 degrees. I was hoping to find one with a shockingly high temp or even find one noticeably warmer than the other to indicate lots of friction in the bearings, but maybe that wouldn't really show up the way I was hoping to find it?

When the wheels were off, I noticed that my right rear tire has noticeable damage to many of the various tread blocks, where the other 3 tires looked perfectly normal (i.e. rear tires were both down to 5/32" to 6/32" tread, fronts had a bit more left though show the extra wear on the inside shoulders that I've always seen on this car and have taken to be quite normal for our stock suspension setup). If this makes sense- probably 10-15% of the individual tread blocks have small chunks missing at various locations around their perimeter, almost as if some took a razor blade and cut tiny chunks off. Some still had the damaged chunks hanging on slightly. Wondering if this might be an indicator of something at that corner, like the wheel bearing or other suspension piece causing vibration or allowing play that is putting friction or stress on the tire outside the normal range of what a tire should experience?

I've been living with the sound for almost 2 years now, and I don't want to keep ignoring it, but I'm not yet ready to swallow my pride and pay someone else to fix it. I've done all the maintenance and repair on this car from when I got it 6 years ago with 28,000 miles to today with 135,000 miles. I'm capable of getting the rear hub assembly off and would likely bring it to a shop to press out the old bearing and a new one in, but I'm not exactly warm to the idea of paying a dealership the $700 or $800 I was quoted over the phone when I asked about replacing a rear wheel bearing.. and even a small local shop would be several hundred dollars more than if I buy the bearing myself and DIY. That's money that's needed for home projects and the like with a family and all.

Please take a listen to these videos I took yesterday and offer any insight or opinions you can!

 

Quick extra notes- sound does not change if I put the car in neutral and even turn the engine off.

Additional thought I forgot to mention- Any thoughts on if my differential could be to blame? Could it produce a speed-dependent humming noise if there was a problem with it? If so, would it be likely to continue for so long without showing any other major symptoms? Any way to diagnose a diff problem aside from looking for excessive wear material stuck to the magnet on the drain plug or removing the case cover to visually inspect?

What is a normal amount of metallic sludge/particles to find on the magnet after 30,000 miles? I think the last two times I've changed the fluid, there's been maybe about half a pea sized amount of very fine metal shavings (more like a dust, but sludgy because of the oil). Is this typical? It didn't raise any alarms to me, but of course now I'm wondering.. I'm considering changing the fluid early (15,000 miles on it now) and sending some to be analyzed by Blackstone Labs.

 

:bump:
Over 300 views and no one has any thoughts to add? Anyone?

Bueller..? Bueller...?

 

I have the same issue. Haven't figured it out yet, but like you I suspect a wheel bearing. When I find a definite answer, I will let you know!

 

I have noticed there's a slight but noticeable vibration that I can feel in the 24-28 mph range, and ever so slightly it seems to be more pronounced when turning to the right and less pronounced when turning to the left. I also have (just in the last month) noticed a slight metallic scraping /scratching noise from the driver side when I have my window open. It's not very loud, but I can hear it clearly when I'm driving next to a wall or something else that the sound can bounce off of to come back towards the car and my ears. I think this support the culprit being a bar rear bearing on the driver side. I'll have to get it back off the ground and play with that driver side rear wheel to see if I can hear the noise up close or maybe finally feel it. In any case, I better start reading through the DIY on swapping the rear bearing and make some calls to find a shop that will press the bearings for me.. the few that I called before didn't want to do the work, only wanted to take it if they did the entire job for me :eyeroll:

 

For shish-and-giggles, I went to the Nissan stealership near my work over lunch. Long story short, here's what I was quoted:
Rear Hub assy: $273
Rear bearing assy: $170
Press bearing onto hub: $100
Full install on vehicle: $325 Labor + parts

Over $800 once you add tax to have them replace a single rear wheel bearing. This! This is why I like to do the work on my car myself!

I know an independent shop should be cheaper, but reasoning still stands. And yes, I know I may not need a new hub, but I have been driving with the bearing going bad for almost 2 years. Up to a month ago, the only symptom was the loud hum (no perceptible play or roughness in hand-spinning any of the wheels) , so I couldn't isolate the exact source. Now there's some metallic noises coming from drivers rear and slight vibrations at a few specific vehicle speeds, definitely indicating the bearing is deteriorating and making we worry the hub has been stressed enough that it may be out of spec.

Just need to find a reasonable quote on pressing the bearing, then I can order the parts and get that done ahead of time and won't need to use my wife's car to drive to a shop while leaving her and the kids stranded at home with my car on stands.

 

I'm used to talking to myself at home when my kids and wife are zombified by electronics in front of their faces, but it's still weird to see 1100 views and no one wants to chime in with anything..?

Anyone know of a good place to find the rear hub assembly? I can find the bearing (and I keep reading Timken is the way to go) everywhere, including RockAuto. I can't seem to find the hub anywhere but eBay. On eBay, there are plenty of listings that appear to be both the hub and bearing, and some even appear to have the bearing pre-seated (one seller has two listings that look to have the same parts, but one is $20 more, and pictures seem to show assembled vs separate).

The problem is, the listings for the hub assemblies all seem to come with bearings, and I haven't found any that come with bearings from a reputable brand. They all just have "Aftermarket like OE brand" for the brand. It may very well be a Timken (or NTN) or even just another brand that would be of perfectly fine quality, but that's an unknown I'm not comfortable with.

I'd rather buy the bearing knowing it should be a quality part, and buy the hub also, then deal with getting it pressed in once I have it. Suggestions on finding a (quality) hub??

 

Hmm.. I found a few now. Got the part number from riversideinfiniti.com. 43202AG000

I found it on NissanPartsDeal for a reasonable price, but my searching also turned up an aftermarket option on Amazon that just seems too good to be true, even though there are 3 positive reviews to back up that it works. It's a case where they price their part so low, though, that it makes me nervous to actually buy it! We're not talking about something like a cheap phone charger that if it stops working, I just get another..

http://www.nissanpartsdeal.com/parts...202-ag000.html

 

I had a similar humming noise/vibrating coming from the front of 04 coupe last year .. Only got louder as I accelerated and didn't stop until the car came to a stop
I got a few opinions on it and was told it was my front wheel bearings
I was able to order 2 of the hub bearing assemblies for cheaper than one and didn't want to deal with pressing them out/in ( so why not lol ) from 1aauto.com .. I don't remember how much I paid exactly but it was a really good deal so I jumped on it and shipping was quick & everything looked good
I replaced both the front assemblies .. Once I took off one of the bearing I compared it to the new one and that's when I realized it was bad . With my new hub I would spin it and it would be a real SMOOTH turn .. With the bad hub , once it was in my hand and tried to turn it , it would turn but was kind of rough and bumpy .. No where near as smooth as the feel of the new hub. On the car you wouldn't be able to tell if it's bad or not or even feel that "rough/bumpy" spin. Absolutely no wobble or play within the hub and bearing even when yanking on it with the wheel on ..
The assembly on the other side (passenger) felt really smooth just like the new one it just looked dirty lol . It didn't need the new one but it was already off and had the new one on hand .. So why not
I'm no master mechanic or anything but give that a try and take off one of the bearings and feel for that smooth or roughness when you spin it .. Might just be it
Good luck

 

Thanks, sergioo. Unfortunately, the rear bearings are different than the fronts in that the fronts come as a hub+bearing complete assembly, you don't reuse the hub, and (at least on non X models) it's a much easier task to remove and inspect, since there's no axle involved. If I was suspecting a front bearing going bad but couldn't tell with it on the car, I probably would go to the trouble of removing it from the car to inspect it before ordering the parts. There are too many examples of people on this board having the rear bearing become separated when removing it from the car, I can't take the chance of removing it to inspect without having a replacement ready to go back on the car. I just don't have the option of leaving my car undriveable outside of the weekend.

 

Here's the method I've employed for the last few wheel bearings I've done on my car (4).


I bought a knuckle on Ebay. You can find them with various parts still attached, ut I got the complete ones with an old bearing hub and dust shield for $100. Some of the RWD ones come with the drum brake parts attached.

The bearing goes in the trash and I basically assemble the entire thing on a bench with new parts taking my time. Then when comes time to do the job, I am pretty much just swapping out the knuckle, which doesn't take that long.

My car is daily driver, so I try to minimize downtime as much as possible.

When done, sell the knuckle on Ebay. Underprice all the others and it goes quick. Even if you take a $20-30 loss, the convienence it gave you was well worth it

 

Ok, got the driver side rear bearing changed this week. Made a HUGE improvement, so it was definitely the bearing in the video. Once it was off the car, I turned it in my hands, and I could feel and hear the metallic grinding.

I still hear another bearing that's going bad, making the same type of noise, where the groan/hum changes pitch relative to the speed the car is moving at. However, it is MUCH less loud. It's almost like I'm wearing earplugs, with how much quieter the car is at 20 mph and up.

I'm guessing I'll need to do the other rear bearing sooner than later. Hopefully that'll be it, but it's such a low frequency noise that it's difficult to judge the direction, whether the sound is definitely coming from the rear.. maybe it's so hard to tell because I have another bearing (or both) worn out up front, too..

 

LOL Marlin don't feel so bad... I think my rears are going bad also. Do you run any wheel spacers or low offset rims. I run 30 mm wheel spacers on the rears with a 10" wide rim +32 offset rim, and 275 width tire. My noise usually happens at about 55 mph and I really don't get any shaking just a noise and seems like rubbing. It goes away though and wont do it sometimes for days. I hope its not the bearings, but I'm not sure. I have had the spacers on for 2 years and I never have taken car to the track and I baby the car. I never had any problems with it till recently.

 

Nope. I'm all stock, non-sport suspension. I'm at 137,000 miles, now, though. And I've had 2 or 3 low-speed, minor sideways curb impacts.. I can think of 2 that were on the passenger side, from sliding one ice in the "Snowpocalypse" here in Atlanta a couple years back. They were very minor, though, under 5 mph. No evidence left on the wheels or tires.

 

Lol... I live in metro Atlanta also and my G wouldn't go no where in that storm. I parked my car in a nice neighborhood on the way to my house and rang the guys door bell and asked him if I could leave my car at the front of his house while this storm passes. About a week later I finally get my car back and he goes I see why you left it here, it's a really nice car. I almost got rear ended several times in that snow storm so I parked that car.