2009 Mazda 5: Rear Wheel Bearing Replacement?

[bglav]

Hi All,

Our 2009 Mazda 5 slid off the road in ice this winter and was pulled out by a tow truck. Since then, we have had a very loud hum coming from the rear of the vehicle which gets louder at higher speeds. I assume one of the wheel bearings is bad.

A few items I've read indicate the bearing is not serviceable by itself, but the whole hub assembly should be replaced.

I called the local Mazda dealer and it took him a while to give me a price. They quoted be me $355 to replace the bearing. I asked if they could replace only the bearing and he said, "Well, I looked it up with another service writer and he found the part on alldata, so I'm pretty sure you can replace it" - Didn't sound too confident

2 questions:
- Is the bearing itself replaceable?
- Is this something a novice could handle? I've done brakes and oil changes, but nothing else major

 

[hibern8r]

Actually, Its been a pretty long time since I've seen a vehicle that uses the bearings and a "race", The hub assembly needs to be replaced as a unit. Here's a link to it at partsgeek~~~>http://www.partsgeek.com/catalog/2009/mazda/5/driveshaft_-ar-_axle/wheel_hub_assembly.html. If you can do brakes, I'm confident that you can manage this on your own.

 

[bglav]

Actually, Its been a pretty long time since I've seen a vehicle that uses the bearings and a "race", The hub assembly needs to be replaced as a unit. Here's a link to it at partsgeek~~~>http://www.partsgeek.com/catalog/2009/mazda/5/driveshaft_-ar-_axle/wheel_hub_assembly.html. If you can do brakes, I'm confident that you can manage this on your own.

I guess I'm glad I didn't bring it in to the dealer - I pushed back about the ability to replace the bearing and they were not budging.

I ended up taking it to a local mechanic and they are having a really tough time finding where the noise is coming from. They say there is no play in any of the wheels. Ugh...

 

[j3nsmz5]

Since front wheel drive cars have rear wheels that are free spinning and are not connected to an axle, I determined my rear bearings were bad, on my other car, by lifting one side of the rear wheel high enough so I can spin it. I then lifted the other side and spun that wheel as well. One wheel made a grinding noise while I spun the wheel. The other wheel sounded smooth without any unusual noise. The grinding noise was therefore the indicator the wheel bearing has gone bad. The replacement do come as a hub unit. The noise did go away after replacing the one wheel that made the grinding noise.

I would also check the tires. Badly or uneven worn tires can also cause the humming noise.

 

[loosenut]

It seems modern day sealed bearings make noise long before they exhibit any free play. It is serviced as a complete hub assy and is fairly easy to do as it bolts in. If it's something you want to try doing yourself, try to determine which side is making the noise, but if you're wrong both sides are the same so it could just be switched to the other side.

 

[Vasy]

Another good way to check, is temperature difference, unless both failed at the same time.
You just get a laser thermometer and check the difference after a 30-40 minute drive, there should not be more then 2-3 degrees.
If one is getting much hotter compare to the other, replace it.

 

[hibern8r]

It seems modern day sealed bearings make noise long before they exhibit any free play.

Very true!

 

[Silentnoise713]

@ OP. Google the same thing for Mazda3 (same car). Lots of info out there.

Another good way to check, is temperature difference, unless both failed at the same time.
You just get a laser thermometer and check the difference after a 30-40 minute drive, there should not be more then 2-3 degrees.
If one is getting much hotter compare to the other, replace it.

That's neat! Will have to keep this in mind though this means I need to buy a laser thermo… Now, what if BOTH bearings are bad -how would you know?!

 

[bglav]

Thanks everyone! Local mechanic determined that the front right wheel was making a constant noise, while the rear left was sporadic. He's going to start with front right.

 

[Vasy]

Thanks everyone! Local mechanic determined that the front right wheel was making a constant noise, while the rear left was sporadic. He's going to start with front right.

Many recommend with bearings, like brakes, do them in pairs and by the way it sounds, you need all 4. You can probably do rears yourself by getting a free tool rental from Autozone, fronts can be a real beatch due to rust and often best left to the shop.
Once rust is there, the 2nd one will go soon and might as well handle it at once.

 

[Swenny]

Many recommend with bearings, like brakes, do them in pairs and by the way it sounds, you need all 4. You can probably do rears yourself by getting a free tool rental from Autozone, fronts can be a real beatch due to rust and often best left to the shop.
Once rust is there, the 2nd one will go soon and might as well handle it at once.

I would agree that doing them in pairs is probably good. On my previous minivan I changed the front left bearing only because of noise. 6 months later I had to do the front right