2016 CX-5 GS Humming over 80km/h!?

[Irenicus]

Just bought this thing a few months ago and never really noticed the humming phenomenon whenever you get around 80km/hr on the highway. It feels intermittent - it humms loudly for about 4 seconds then stops for 2 seconds, on for 4 seconds, off for 2 seconds. I'm really not sure if it's the tires or bearings or whatever else. It was just serviced at the dealership before I bought it..

What's the first thing to look for here? I'm not much of a car guy, I guess it could be a wheel bearing.

 

[RedBaron]

That's one of the classic wheel bearing symptoms for sure

 

[Irenicus]

It also has a weird crunching sound when the wheels cranked all the way left and in motion. Think it’s a CV… with only 86k on the vehicle it seems unusual. $200 to diagnose it at a shop… ugh. Any other ideas? Also no idea why an axel is $130 online but they quote me $500-1100 for one at the dealership

 

[Mazdiod2]

It also has a weird crunching sound when the wheels cranked all the way left and in motion. Think it’s a CV… with only 86k on the vehicle it seems unusual. $200 to diagnose it at a shop… ugh. Any other ideas? Also no idea why an axel is $130 online but they quote me $500-1100 for one at the dealership

$130 for re-manufactured?

 

[Irenicus]

$130 for re-manufactured?

I just googled CV axle and that’s what came up .. no idea. Not sure what to do, kinda sucks

 

[Mazdiod2]

Get some more opinions and try to figure out exactly what's wrong if possible.

 

[Irenicus]

Shop says it's a front left wheel bearing but haven't addressed the weird crunching sound when turning all the way left.

Regardless sounds like I'm going to replace the bearing hub. Few questions
- Is it worth it to replace both front bearings at the same time? My buddy says 100% replace both
- Should I be okay to buy some really budget economy hub assemblies online? I'm looking at this site and they have ones all the way from $102 to $280 and even up to $390 at local part stores. I guess the main difference is a warranty length.

Shop quoted me $700 plus tax to replace the bearing but I can do it myself and save a ton

 

[RedBaron]

If the car is older (as is yours), the hubs tend to rust on to the carrier and can be an absolute BEAR to remove (ask me how I know). If you are not a proficient mechanic, you might just want to have an indy mech do it.

I would just get a reputable aftermarket set and replace it/them. I would say yes, replace both. But then I only replaced one on my 2014, so who am I to say otherwise

 

[sm1ke]

Shop says it's a front left wheel bearing but haven't addressed the weird crunching sound when turning all the way left.

Regardless sounds like I'm going to replace the bearing hub. Few questions
- Is it worth it to replace both front bearings at the same time? My buddy says 100% replace both
- Should I be okay to buy some really budget economy hub assemblies online? I'm looking at this site and they have ones all the way from $102 to $280 and even up to $390 at local part stores. I guess the main difference is a warranty length.

Shop quoted me $700 plus tax to replace the bearing but I can do it myself and save a ton

In my experience, it's worth it to pay for wheel bearings. Not necessarily OEM, but good quality replacements are way better than the cheapest offerings, unless you're just looking to unload the car right after you replace them. I have a 2018 CX-9, and I had to replace my front wheel bearings last year due to some bad pothole hits. My mechanic also recommended that I replace both wheel bearings, so I went out and bought some cheap GSP branded front wheel bearing hubs at his recommendation. They were around $110 per side, while quality hubs were $180-300 per side for brands like SKF and Timken. The new hubs fixed my issues, but now there is a very quiet, but consistent rubbing sound, like when you run your fingers over a metal surface. I'd buy SKF and Timken hubs next time, for sure.

If the car is older (as is yours), the hubs tend to rust on to the carrier and can be an absolute BEAR to remove (ask me how I know). If you are not a proficient mechanic, you might just want to have an indy mech do it.

To add, there may also be issues with removing one of the sensors without damaging it. I live in an area where vehicles are prone to rust and corrosion from all the road salt that's spread in the winter. The OEM hubs didn't rust to the carrier too bad, and my mechanic was able to get them off fairly quickly with the right tools. Those sensors, however.. we must have spent 2-3 hours on sensor removal alone, using penetrating oils, small picks and screwdrivers to gently remove them without damaging them.

Meanwhile this guy took them off with zero issues, in less than 10 seconds lol. @Irenicus, if you do decide to DIY this, that video is a decent resource to show you how to replace front wheel bearings.

 

[RedBaron]

The OEM hubs didn't rust to the carrier too bad, and my mechanic was able to get them off fairly quickly with the right tools. Those sensors, however.. we must have spent 2-3 hours on sensor removal alone, using penetrating oils, small picks and screwdrivers to gently remove them without damaging them.

Hah! I found the opposite. Sensors came out without too much trouble. Hubs were rusted tight.

I ended up using a mallet and a wood chisel to try to insert and pry all around the hub. It came out eventually, but I broke the chisel end

 

[Irenicus]

Okay good call I’ll get a reputable brand

Do I really need to change both hubs though? The mechanic who I trust says there is no reason to change both fronts if it’s not needed. I see the logic on both sides

Also, do I need a hub with the sensor wire? Some of the hub assemblies online come with wired attached but they all spec as fitting the 2016 GS.

 

[RedBaron]

Also, do I need a hub with the sensor wire? Some of the hub assemblies online come with wired attached but they all spec as fitting the 2016 GS.

If you can get the old sensor out undamaged, then you don't need it. If you break the old sensor though, you'll need it . As I said, mine came out fairly easily, but YMMV.

 

[Irenicus]

If you can get the old sensor out undamaged, then you don't need it. If you break the old sensor though, you'll need it . As I said, mine came out fairly easily, but YMMV.

What is the sensor for anyway? Looks simple enough with a 10mm socket

Also, replace both bearings or just the one?

 

[Irenicus]

Also

Anyone have opinions on brands for wheel hubs?

Quoted pretty cheap for a GSP one but have been looking at SKF and Moog. Guy said he’s never had a problem with the GSP ones before but they seem a lot cheaper than an SKF

 

[RedBaron]

What is the sensor for anyway? Looks simple enough with a 10mm socket

Also, replace both bearings or just the one?

It's the wheel speed sensor, primarily for ABS. Getting the retaining bolt out is not the problem. Getting the sensor itself out is the problem. The body of the (plastic) sensor is a cylinder inserted into a hole in the hub carrier and can get stuck tight and possibly break when trying to twist/lever it out.

I already gave you my opinion on replacing one hub or both above. But why not just follow your mechanic's recommendation? If you replace the one side, worst comes to worst, you be back months/years later to do the other side. But the labor cost would be the same if you did that, or did them both now.