Wheel bearing

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69
Location
Ohio
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One of our cars has developed a roar coming from the back passenger side. This occurs only at speeds above 55 MPH. There is no play in the bearing and the wheel rotates without any detectable roughness when spun by hand. The roar comes and goes with a period of about 1 minute. The roar is only slightly modified by turning the car a bit to the right or left. I've never had a bad wheel bearing present in quite this way, so I appeal to those with much greater experience: Can this roar be caused by a bad wheel bearing? The problem is not the tire as I have rotated the tires without any effect on the roar. The bearing in question is a National bearing replaced by me about six years ago. I used a torque wrench to install it. Were the National bearings of about six years ago of poor quality.? The bearing has about 30,000 miles on it. Thanks for any help with this question.
 
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16,375
Location
NH
What is the make and model? Are you sure it's not the bearing on the other side? I've always done bearings in pairs--if one side is going, the other can't be far, that is my reasoning. So far that has been true across three sets (granted that's a limited dataset I know).
 
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69
Location
Ohio
Thread starter
Originally Posted by supton
What is the make and model? Hyundai Elantra Are you sure it's not the bearing on the other side? I've always done bearings in pairs--if one side is going, the other can't be far, that is my reasoning. So far that has been true across three sets (granted that's a limited dataset I know).
That's a good point, but the bearing I replaced six years ago was not bad--I was fooled by a bad tire. I saved that OEM bearing and am thinking about putting it back in.
 
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21,084
Location
Apple Valley, California
Originally Posted by supton
What is the make and model? Are you sure it's not the bearing on the other side? I've always done bearings in pairs--if one side is going, the other can't be far, that is my reasoning. So far that has been true across three sets (granted that's a limited dataset I know).
You would think they would wear in pairs but they don't. I put one in our Tahoe @116k. It now has 182 k and the one on the other side seems fine.
 
Originally Posted by Chris142
You would think they would wear in pairs but they don't. I put one in our Tahoe @116k. It now has 182 k and the one on the other side seems fine.
Road crown and the loaded side (almost always the passenger side) will take much more abuse from the vehicle weight and impacts than the less-loaded side. Subaru "flat" wheel bearings in the older Imprezas and Foresters have always been more wear-prone than on the tapered wheel bearings in Legacy/Outback and newer Subarus. Not sure if yours is flat or tapered.
 
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21,084
Location
Apple Valley, California
Originally Posted by SubieRubyRoo
Originally Posted by Chris142
You would think they would wear in pairs but they don't. I put one in our Tahoe @116k. It now has 182 k and the one on the other side seems fine.
Road crown and the loaded side (almost always the passenger side) will take much more abuse from the vehicle weight and impacts than the less-loaded side. Subaru "flat" wheel bearings in the older Imprezas and Foresters have always been more wear-prone than on the tapered wheel bearings in Legacy/Outback and newer Subarus. Not sure if yours is flat or tapered.
Funny that I replaced the dr side! the ps side is still going.
 
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3,913
Location
SW Ohio
Originally Posted by toad
The roar is only slightly modified by turning the car a bit to the right or left.
I think that's a fairly definitive sign that it is the wheel bearing. When you say "right or left", it should really be one or the other, not both (unless both bearings are coincidentally bad at the same time). While driving, if you gently swerve or weave left and right, the noise should be noticeably different in one direction or the other. If you turn left and it gets quieter, I believe that suggests the right-side bearing is the culprit (turning left, you transfer weight OFF of the right side). Play in the assembly isn't always noticeable (enough). I've also seen people use an infrared thermometer after driving. The one with the higher temperature should be the bad one.
 

Kestas

Staff member
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13,723
Location
The Motor City
Your description matches nearly word-for-word the scores of customer narratives I've read while handling wheel bearing warranty for our company. You have a bad wheel bearing. The reason you dont detect looseness is because a bad wheel bearing will make noise long before it starts developing looseness. They don't necessarily go bad in pairs. In fact, we only allow the dealers to replace the bad bearing and not the pair.
 
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69
Location
Ohio
Thread starter
Quote
Play in the assembly isn't always noticeable (enough). I've also seen people use an infrared thermometer after driving. The one with the higher temperature should be the bad one.
I actually did something similar: after touching both sides right at the bearing and thinking that I detected that one was slightly warmer I held a thermistor covered with several layers of rag against the bearings and the one with the noise was warmer.
 
Messages
69
Location
Ohio
Thread starter
Originally Posted by Kestas
Your description matches nearly word-for-word the scores of customer narratives I've read while handling wheel bearing warranty for our company. You have a bad wheel bearing. The reason you dont detect looseness is because a bad wheel bearing will make noise long before it starts developing looseness.
I'm going to replace the bearing right now and take it for a drive.
 
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7,824
Location
Champlain/Hudson Valley
Left rear bearing in the '76 solid axle Ford E-100 van. Everyone said to leave the other alone. RF on the 2002 Volvo. So separate the bearings are I went with just replacing the bad one. RF on a 2012 Mazda3 under warranty. Dealership needed 2 overnights to schedule and did both. I wondered if Mazda knew/learned of a bad batch of bearings and did both. The other one failing would rumble the same causing a customer to conclude the repair was thievery. It would fail out of warranty. I saw a mid '80's Acura Legend V6 today.....speaking of bearing life
 
Messages
69
Location
Ohio
Thread starter
Thanks for the replies. Replaced the bearing and the noise is gone. Are National bearings generally that bad (failure at 30,000 miles), or did I just get a bad one ?
 
Messages
16,375
Location
NH
Dunno, they seem to go in pairs for me. 2004 Jetta, mechanic wasn't quite sure which side on a test drive, but I had said I wanted both. Once on the lift, with the axles out of the way, both felt gritty. Saved me a second trip (this garage was 2.5 hours from home). Later, the wife's 2001 Civic got the same noise, around 140k, replaced one. The other side went out the following year. And on my Camry, I did both rears at the same time, pretty sure both felt bad. shrug For me, scheduling to have both done at the same time costs me less time and headache. I can see why under warranty only one would be done, but after 100k I plan to just shotgun both if I'm paying someone else to do it.
 
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