noclutch

Hey all. Almost 90k down the road since new and hoping I can get some insight into a somewhat ongoing problem.

There is a speed dependent hum or whine that seems to be coming form the rear drive train/rear end of the car, most noticeable when going 30-80 mph, pitch somewhat proportional to speed. It is apparent starting at around 30 mph but is sort of low hum and not very noticeable, but as speed increases it gets louder and slightly higher in pitch.

I first brought it up to my dealer service advisor at around 60 k miles, and he chalked it up to "cupped tires". They were the second set, about 1/2 worn and mounted with an alignment and road force balancing. And I didn't see any cupping so I just let it lay there.
Fast forward a couple of years and now at 87k and on a brand new set of Michelins the vibration noise is still there and seemingly progressing, or it's just bugging me more. No CV joint noise that I can detect. Rear differential has been changed pretty much on schedule. Also an alignment was done with this set of tires as the front struts were replaced as well.

According to my cell dB app*, it's saying around 75-80dB at freeway to highway speeds- very annoying.

FWIW, when the car was fairly new, I had the front seat vibration issue which was addressed according to TSB 16-057 and that seemed to help, but not totally resolve it. But I'm wondering if these things may be related?

Also, I'm 62 and don't hot rod around- this is my daily driver and don't pretend that it's a serious sports car nor that I have above average skills, but I will wind her out now and again

Anyone with a SHAWD with similar vibration/whine/hum/noisy issues in here?

18TLXAspec

Does it change any if you make the swerve from side to side? If so, could be a wheel bearing. Probably best to have a tech diagnose it.

noclutch

Nope- turning or swerving makes no appreciable change. It’s ever-steady and proportional to speed ( so not transmission related I’d assume. I’m thinking rear differential or u joint🤷🏻‍♂️

18TLXAspec

Could be the AWD transfer case.

noclutch

On second thought after much annoying listening, yes it does change.
In a sweeping corner to right at highway speed, it gets quieter than going straight. And sweeping to left, nosier than going straight and fair amount noisier than going to right.

So maybe wheel or axle bearing on the right rear, which would bear more weight and/ or lateral forces while turning? Again it is a SHAWD fwiw.

noclutch

FWIW -Turns out it was the right rear spindle carrier bearing. Alls quiet now 👍🏻

finebead

I had a hum in the rear wheels at about 50K miles on my 2015 TLX v6 tech. I took it to the dealer and one wheel bearing needed to be replaced. They did it under warranty. I was surprised that a wheel bearing went out at 50K miles, didn't expect that.