ND MX-5: 2016 Miata Club 6sp - grinding/friction noise not bearings

[Ninja_Matt]

Hey everyone! New to the forums, I have a 2016 Miata Club 6spd with 42k miles on the clock. It has done a lot of sitting over the past few years and I developed a loud grinding/humming that was wheel-speed dependant a couple of years ago. I had it diagnosed as the driver rear bearing, but the car sat for a while after. I finally got around to replacing the rear driver hub assembly and replaced all 4 brake rotors/pads along with it (original rotors). Car drives much better now, however to my surprise while the loud noise I was experiencing improved a lot - it did not go away. I told the mechanic it might be the passenger rear hub but he said the driver rear was clearly bad but the rest of the hubs were tight with no play. It is clearly some sort of metal friction sound and is definitely wheel speed dependant, getting worse at higher speeds. I don't believe it is tire noise, or at the very least not solely that. Could it be diff related? I would expect that to be more of a whirring/whining sound but can a diff cause this sound? The sound is similar to a bad bearing or how it sounds when you use your brakes with rusted rotors.

Thank you in advance, hope to get some good help here!

 

[njaremka]

Did you replace the passenger wheel bearing? Usually you can determine if it is a wheel bearing and what side by driving the car from side to side, loading and unloading the wheels. As you load a bad bearing, it should get louder.

Also, are you a member over at miata net?

 

[Ninja_Matt]

Did you replace the passenger wheel bearing? Usually you can determine if it is a wheel bearing and what side by driving the car from side to side, loading and unloading the wheels. As you load a bad bearing, it should get louder.

Also, are you a member over at miata net?

Thank you for the reply, I did not replace the passenger side bearing, will probably do that just to be safe if I can't find another potential cause to the problem. I am a member on Miata net and used to be very active especially when I first got this car ~8 years ago. Wanted to check out Mazdas247 and figured I'd give it a shot on here

 

[stefoz]

Hey everyone! New to the forums, I have a 2016 Miata Club 6spd with 42k miles on the clock. It has done a lot of sitting over the past few years and I developed a loud grinding/humming that was wheel-speed dependant a couple of years ago. I had it diagnosed as the driver rear bearing, but the car sat for a while after. I finally got around to replacing the rear driver hub assembly and replaced all 4 brake rotors/pads along with it (original rotors). Car drives much better now, however to my surprise while the loud noise I was experiencing improved a lot - it did not go away. I told the mechanic it might be the passenger rear hub but he said the driver rear was clearly bad but the rest of the hubs were tight with no play. It is clearly some sort of metal friction sound and is definitely wheel speed dependant, getting worse at higher speeds. I don't believe it is tire noise, or at the very least not solely that. Could it be diff related? I would expect that to be more of a whirring/whining sound but can a diff cause this sound? The sound is similar to a bad bearing or how it sounds when you use your brakes with rusted rotors.

Thank you in advance, hope to get some good help here!

@Ninja_Matt Same thing with my 2016 ND after rear collision (open diff not limited slip). Pinion bearing suspected as faulty. Definite diff problem anyhow.

 

[Ninja_Matt]

@Ninja_Matt Same thing with my 2016 ND after rear collision (open diff not limited slip). Pinion bearing suspected as faulty. Definite diff problem anyhow.

Interesting, I was away out of the country for a week but probably going to do a diff fluid change and trans fluid change and see how that affects the noises, then move to the other rear hub and see if that gets it - getting close but havent ever replaced the diff fluid and the car was built in 2015, probably could use it no matter what.

 

[stefoz]

Interesting, I was away out of the country for a week but probably going to do a diff fluid change and trans fluid change and see how that affects the noises, then move to the other rear hub and see if that gets it - getting close but havent ever replaced the diff fluid and the car was built in 2015, probably could use it no matter what.

lots of black on the magnet ? then I would suspect diff.