[CardigansFan]

2016 Mazda 6 sport, automatic, about 160k miles through midwest winters. One or both of my front wheel hubs need replacement (never replaced to my knowledge and starting to make noise and mildly affecting driving) and all rotors have been resurfaced / worn down to their limit (seeing vertical lines on them), so I figure it would be a good idea to replace them all around. The local Mazda dealership wants about $3200 including alignment, so I'm opting to get new OEM hubs and OEM-equivalent rotors and do it all myself and bring it down the street for an alignment afterward.

I've replaced hubs / axles / etc on a 2007 Subaru Outback and know that it's not very difficult to do (and rotors being even easier), but is there anything noteworthy or unusual in replacing hubs on the Mazda, especially with no CV axles in the rear like with the Subaru? Almost everything in the wheel areas has already been replaced recently otherwise and I'll probably get a full set of replacement mounting bolts and splash shields after dealing with the infamous issue of the absolutely seized rear strut bolts, so it shouldn't be too hard to remove them even if it means destroying them in the process.

For that matter, I had to replace the passenger side CV axle recently due to a torn boot and other issues. Would it be a good idea to replace the driver side CV axle, with the minimal extra work involved and at this mileage? I'd hate to replace the hubs only to find that the CV axle is also failing (or getting extra wear from the bad hubs) and dealing with all that work and an alignment again, but it's also a ~$400 part and I'm not sure how much life I should be getting out of it. I opted to pay the dealership to replace the passenger side one, but the driver side seems much easier to do with no intermediary shaft to deal with. I looked at a video and it doesn't look like I even need to replace any fluid in the process of pulling the axle?

 

[TalonTsi90]

What makes you think you need hubs? Do not get "oem" rotors, see my sig.

 

[CardigansFan]

What makes you think you need hubs? Do not get "oem" rotors, see my sig.

I've replaced shocks / struts / springs / end links all around as well as tie rod ends and an alignment after all of that, have new 16" tires (Yokohama Avid Ascend GT) and lightweight wheels (Enkei RPF1) properly balanced, I tightened everything down to spec (including a loose driver side axle nut in one instance), and the calipers and control arms were replaced before I got the car and seem fine -- and despite all of that, there's a humming noise of sorts that's gotten worse over the last few weeks, as well as very slight weirdness to the driving feel that I can't explain any better than feeling out of alignment despite being in alignment. All signs point to failing wheel hubs, unless it really is just a bad alignment, but I'd hate to waste the money on one only to find that it is in fact the wheel hubs.

And yeah, wasn't planning on OEM rotors, no sense paying $70+ each when equivalent ones will work the same and include protective coatings on the hub portion. I do want OEM for hubs and axles, though.

 

[TalonTsi90]

You have 16" tires on a car that comes with 19" wheels and wonder why it feels weird? Id really bet its not the hubs, but do the proper test before you do cause ive not heard of any 3rd Gen needing them yet.

 

[tickerguy]

I have more than double your mileage and my hubs/bearings are fine.

 

[CardigansFan]

You have 16" tires on a car that comes with 19" wheels and wonder why it feels weird? Id really bet its not the hubs, but do the proper test before you do cause ive not heard of any 3rd Gen needing them yet.

The current tire / wheel combo is within 1% diameter difference compared to the 17" wheels it came with, so I figured the added sidewall would dampen noise and vibrations. But I guess losing 10lbs per wheel may have some unintended consequences as far as noise / vibration dampening or overall car feel? I originally replaced the wheels because the stock ones were curbed and dented all over and felt like they were affecting the driving and balance, and figured I'd go with a lighter wheel and more sidewall for a comfier and snappier ride.

What would you suggest for the test? Do you mean using equipment to test it myself, or paying for diagnostic service at the dealership?

 

[TalonTsi90]

But I guess losing 10lbs per wheel may have some unintended consequences as far as noise / vibration dampening or overall car feel?

It could. I dropped 27# when i went lithium battery and the car drove funny for the first couple weeks.

The first bit before taking the wheel off is all you really need, go further in the vid if you think you need to.

How to: Check a wheel hub bearing assembly - YouTube

 

[Zoom Zoom 4Ever]

. . .
For that matter, I had to replace the passenger side CV axle recently due to a torn boot and other issues. Would it be a good idea to replace the driver side CV axle, with the minimal extra work involved and at this mileage? I'd hate to replace the hubs only to find that the CV axle is also failing (or getting extra wear from the bad hubs) and dealing with all that work and an alignment again, but it's also a ~$400 part and I'm not sure how much life I should be getting out of it. I opted to pay the dealership to replace the passenger side one, but the driver side seems much easier to do with no intermediary shaft to deal with. I looked at a video and it doesn't look like I even need to replace any fluid in the process of pulling the axle?

It's really not necessary to change your DS Cv axle before it's necessary, not with your car being only 6-7 years old. For some maintenance work, it makes sense to replace some things while you're doing other things. For example, if replacing the timing belt (on cars that have them, not ours), it's recommended to also replace the water pump, because the timing belt change takes many hours of labor, and if the water pump goes bad later, you have to remove and retime all the same parts that you handled with the TB change.

Cv joints can fail mechanically without the boots being torn, but it is rare. Usually the sequence of events is:
1. Boot gets torn, either from something catching on it or just worn out from mileage and/or age.
2. Grease from the Cv joint gets slung all over suspension parts in the area.
3. If the Cv axle is not serviced (either rebuilding it or replacing the whole thing), eventually water will mix with the grease, lubrication will fail, and the Cv joint will fail mechanically. This takes quite a long time to happen, often a year or more.

As long as someone, you or your mechanic looks at the car from underneath at least once a year (like at your car's annual inspection) to check for a torn boot, there's no reason to replace a Cv axle until necessary.

I know we are living in times of "replace it" before "can it be fixed?" is even considered, but a Cv axle with a torn boot can almost always be cleaned, regreased, and have a new boot installed for less than $50 if you do the work yourself. There are lots of vids on YouTube showing how to do this.

 

[tickerguy]

The other thing to consider is that if your option for replacement is Chinese what's on there from the factory is almost-always of superior quality. Unless you like doing the job more than once fixing what you have, if it can be, is usually the better option.