2018 sportback knocking in rear end

[2018 TourX in Texas]

My issue MAY be related.
Not a popping noise but a low frequency vibration noise (thought a branch was stuck under the car) - only evident at low speeds like maneuvering a parking lot & only with steering wheel turned L or R.

Noise fades above say 10mph & completely disappears when going totally straight.

Was thinking it could be differential related ?

Just changed rear & front diff fluids using proper spec fluid - maybe rear needs more anti slip additive ?

I will raise rear & verify lube level unchanged.

Any ideas I'm all ears & thank you ahead of time !

David in Texas

 

[ttom2012]

My issue MAY be related.
Not a popping noise but a low frequency vibration noise (thought a branch was stuck under the car) - only evident at low speeds like maneuvering a parking lot & only with steering wheel turned L or R.

Noise fades above say 10mph & completely disappears when going totally straight.

Was thinking it could be differential related ?

Just changed rear & front diff fluids using proper spec fluid - maybe rear needs more anti slip additive ?

I will raise rear & verify lube level unchanged.

Any ideas I'm all ears & thank you ahead of time !

David in Texas

Hi David, in case you have not figured this out. This sounds like the rear diff for me, and you can find threads on this forum. I'd suggest find a way to reproduce the noise reliably and bring it to your dealer under powertrain warranty.

 

[Displayhawk]

My issue MAY be related.
Not a popping noise but a low frequency vibration noise (thought a branch was stuck under the car) - only evident at low speeds like maneuvering a parking lot & only with steering wheel turned L or R.

Noise fades above say 10mph & completely disappears when going totally straight.

Was thinking it could be differential related ?

Just changed rear & front diff fluids using proper spec fluid - maybe rear needs more anti slip additive ?

I will raise rear & verify lube level unchanged.

Any ideas I'm all ears & thank you ahead of time !

David in Texas

This sounds like exactly what my car was doing! I described it to the dealer as a grabbing sound when the car was hot and turning at slow speed. It seemed OK going straight, but I thought I detected a slight vibration at high speed?!?

 

[2018 TourX in Texas]

This sounds like exactly what my car was doing! I described it to the dealer as a grabbing sound when the car was hot and turning at slow speed. It seemed OK going straight, but I thought I detected a slight vibration at high speed?!?

Howdy:

It's been awhile but have you replaced the differential or whatnot ?

I'm thinking it's my issue - pretty certain - and hoping if I spring for it the Buick dealer will be installing an improved unit that will be good for long term.

Any input is appreciated !

David in Texas

 

[LionJohn1237]

Just left dealer. They heard noise loud and clear and traced it to a strut mount. Ordered part for install next week. Will advise !

Hello, Did you ever post the result of the strut mount replacement?

 

[shs92645]

Did you resolve the issue? I’m having the same issue. Mechanic is unable locate. I’m confused either to replace strut mount or rear knuckles.

Yes. Completely fixed and the replacement took about 20-30 minutes.

 

[G-244579]

Yes. Completely fixed and the replacement took about 20-30 minutes.

Thanks! Were both sides changed?

 

[G-505193]

Yes. Completely fixed and the replacement took about 20-30 minutes.

This is different - Mine was determined to be a failed strut, no damping. Replacement GM strut includes the upper mount complete.

Thanks for thieinput!