Grinding noise ONLY in reverse gear.

[Nathan Sauserman]

A little background just bought this truck 2 months ago, last week I went camping with a friend in the bed of the truck. After 2 days, I pulled the truck out of the parking spot in reverse and there was an extremely loud grinding and very loud clunking from the rear end. The noise was so loud people in a cabin 20 yards away came outside because they thought I had hit something. Check engine light came on, pulled code P25A2 and U0146. 

 

Now whenever I use the brake in reverse, there is a loud grinding sound from the rear drivers side wheel. The truck did not make this sound before these codes showed up. It's usually louder in the morning/when it's cold. I've had it at 2 dealerships who say they can't reproduce the noise (by the time they get around to examining the vehicle it has quieted significantly) But the next morning when I back out of my driveway the loud grinding and squealing has returned.

[mjm-1957]

Document ID_ 5625003.htm Hope you can open this. Tsb with both of the codes that you have in your truck.

[Rowe Ingram]

Did you ever find the fix? My 24 1500 with 12,000 makes it too. No clue what causes it

[GMCustomerService]

On 1/18/2025 at 2:30 PM, Rowe Ingram said:

Did you ever find the fix? My 24 1500 with 12,000 makes it too. No clue what causes it

Our team understands how this grinding noise concern can be worrisome, and we would like to take this time to learn more. When you can, please send us an email to [email protected]. Make sure to include your Username and Forum name in the subject line with further details. We will watch for your reply. 

[Mark3362]

I experienced this issue this past year as well on my 2019 Sierra 1500 Denali with 76,000 miles from what I think is the left (driver’s side) rear wheel assembly.  It was so disconcerting at first that I immediately took it to the dealer a few miles away but it wasn’t occurring any longer when I got there. They pulled the wheel and didn’t find anything significant other than a broken brake sensor which they fixed.  I also had them check the parking brake since use it regularly.  Nothing unusual other than a dead mouse in the wheel/brake assembly.  A week later, the grinding occurred again while backing up.  This time, while driving forward slowly, I applied the parking brake until the truck came to a stop.  When I put it in reverse, the grinding did not occur.  About a month later while backing up, it occurred again for a third time and I did the same thing - stopped, drove forward to about 10mph and applied the parking brake until the truck stopped.  Put it in reverse again, no more grinding.   It’s been a few months now since then without a recurrence.  In the meantime, the truck underwent the state safety and emission inspection, and was on the lift to have a rear flat tire removed and repaired.  Nothing out of the ordinary was identified.