Weird noise when reversing (cold)

[15TahoeLT]

Hi all, wanted to see if anyone else here had a similar experience. My 2015 Tahoe (40k miles) makes a strange series of noises when reversing (this mostly happens on first startup when cold, and usually isn't audible once I've been driving it). It almost sounds like a bad/loose u-joint, but its a bit softer of a sound and it usually make more than one "thud", almost like a series of softer thuds before it goes away. I just had the 4WD system serviced by Chevy and they said everything looked good but I know this noise isn't normal. I've read maybe I need a TCM update, but I honestly have no idea. It's not a huge deal at the moment but it's driving me a little nuts.

Thanks for any feedback.

 

[PG01]

Hi all, wanted to see if anyone else here had a similar experience. My 2015 Tahoe (40k miles) makes a strange series of noises when reversing (this mostly happens on first startup when cold, and usually isn't audible once I've been driving it). It almost sounds like a bad/loose u-joint, but its a bit softer of a sound and it usually make more than one "thud", almost like a series of softer thuds before it goes away. I just had the 4WD system serviced by Chevy and they said everything looked good but I know this noise isn't normal. I've read maybe I need a TCM update, but I honestly have no idea. It's not a huge deal at the moment but it's driving me a little nuts.

Thanks for any feedback.

Maybe see if you can get a sound clip.
I would get underneath and touch everything and see if anything jumps out at you. Could possibly be rear brake backing plates rubbing but impossible to even try guessing without hearing it.