2011 Camaro SS differential noise

[GenesisCoupe]

Hello everyone, 100K miles, auto transmission, everything is stock.
In last 2 weeks a sound somewhere from behind has become distinctly audible, similar to the sound of a train accelerating. I can hear it well from 40 to 70 mph. My back tires is cheap Chinese ones, but looks like it's not a tire issue. GM service changed the oil in the diffential, no changes.
Is there any rebuild kit for auto transmission differential? Any part numbers...? Or the cause maybe different?

[bottletalk]

post a video of your car doing a drive by....haha, u know what I mean.
that noise could be several issues, need to hear and see this sound happening. did you look under your car? heavy acceleration worse? does it change when going over speed bumps or on a off camber road/driveway? need more details

[GenesisCoupe]

Originally Posted by bottletalk

post a video of your car doing a drive by....haha, u know what I mean.
that noise could be several issues, need to hear and see this sound happening. did you look under your car? heavy acceleration worse? does it change when going over speed bumps or on a off camber road/driveway? need more details

It is hard to hear on low speeds, and when speed bumps pass, it is not there at all, since the speed is almost zero. I can’t find country roads in the city to check...
Last month my differential removed for CV Axel Shaft replacement and oil was charged that time (sound was before this but was quiter) .
I recorded video but nothing can hear there. I will try again but it is just a howling sound that is audible when decelerating and becomes more subtle above 70mph. It doesn't depend, throttle is depressed or not. Reminds the sound of an accelerating or, on the contrary, decelerating train

[Rock-It Man]

Originally Posted by GenesisCoupe

It is hard to hear on low speeds, and when speed bumps pass, it is not there at all, since the speed is almost zero. I can’t find country roads in the city to check...
Last month my differential removed for CV Axel Shaft replacement and oil was charged that time (sound was before this but was quiter) .
I recorded video but nothing can hear there. I will try again but it is just a howling sound that is audible when decelerating and becomes more subtle above 70mph. It doesn't depend, throttle is depressed or not. Reminds the sound of an accelerating or, on the contrary, decelerating train

First stop should be the shop that changed the axle.

[bannonm]

Originally Posted by GenesisCoupe

Hello everyone, 100K miles, auto transmission, everything is stock.
In last 2 weeks a sound somewhere from behind has become distinctly audible, similar to the sound of a train accelerating. I can hear it well from 40 to 70 mph. My back tires is cheap Chinese ones, but looks like it's not a tire issue. GM service changed the oil in the diffential, no changes.
Is there any rebuild kit for auto transmission differential? Any part numbers...? Or the cause maybe different?

Since you said GM serviced your differential, did they use GM fluid? The problem with GM’s fluid in ‘10-11 cars is the axle seals are not compatible with the revised fluid. The seals will eventually leak unless they have been replaced with the newer ones. I would ask about that.

[bannonm]

Originally Posted by GenesisCoupe

It is hard to hear on low speeds, and when speed bumps pass, it is not there at all, since the speed is almost zero. I can’t find country roads in the city to check...
Last month my differential removed for CV Axel Shaft replacement and oil was charged that time (sound was before this but was quiter) .
I recorded video but nothing can hear there. I will try again but it is just a howling sound that is audible when decelerating and becomes more subtle above 70mph. It doesn't depend, throttle is depressed or not. Reminds the sound of an accelerating or, on the contrary, decelerating train

So after the fluid change the problem was louder? I would bet there’s not enough friction modifier in the fluid they used. Most diff fluids now say they contain the friction modifier but I found with my ‘11 I needed to add additional. Owners manual says 2.5 oz per quart of fluid. I used Amsoil severe gear and their FM and my noise went away after driving 15 minutes. The fluid I had in it previously contained FM but no telling how much. GMs new fluid says it already contains it but not how much.