Something locked up causing me to skit to a halt.

Steve Macedo · April 15, 2023

My 2020 Chevy 3500 DRW locked up twice while towing my 5th trailer at 11,000. 58,000 miles on the truck with no issues to-date.

While driving up a mountain highway at 50 mph. Rear wheels locked up and left 6-8 ft of skid marks. Truck then released and I was able to get it off the road. Crawled under and see nothing loose or leaking. Let the truck sit for probably 10 minutes running while checking. Slowly took off again and no issues at 45 mph and below. 2 miles down the road it happened again with same results. If I had to guess on the 10 speed transmission I would think 6 or 7 gear.

Let it sit and again checking, nothing. Quick search of the web with nothing except torque converters. I received no check engine lights.

Turned around and drove 45 mph and under back down the highway. No issues again. Made it home on country back roads. Had one steep pull out at 35 mph with no issues.

We travel full-time and I baby this truck because I need it to last. Any thoughts

asilverblazer · April 17, 2023

Some amount of searching to find a topic on here about this... but it has happened before to other trucks. I don't remember the solution.

Steve Macedo · April 17, 2023

Thank you. I will continue to search. Going to take it in this morning to see if any codes come up.

GMCustomerService · April 27, 2023

On 4/15/2023 at 4:59 PM, Steve Macedo said:

My 2020 Chevy 3500 DRW locked up twice while towing my 5th trailer at 11,000. 58,000 miles on the truck with no issues to-date.

While driving up a mountain highway at 50 mph. Rear wheels locked up and left 6-8 ft of skid marks. Truck then released and I was able to get it off the road. Crawled under and see nothing loose or leaking. Let the truck sit for probably 10 minutes running while checking. Slowly took off again and no issues at 45 mph and below. 2 miles down the road it happened again with same results. If I had to guess on the 10 speed transmission I would think 6 or 7 gear.

Let it sit and again checking, nothing. Quick search of the web with nothing except torque converters. I received no check engine lights.

Turned around and drove 45 mph and under back down the highway. No issues again. Made it home on country back roads. Had one steep pull out at 35 mph with no issues.

We travel full-time and I baby this truck because I need it to last. Any thoughts

This is certainly not what we like to hear, Steve Macedo. Please know, customer satisfaction is extremely important to us. Our team would be more than happy to take a closer look into the concerns with your 2020 Chevrolet 3500. To do so, please send an email to [email protected] with ATTN: Steve Macedo/GM Trucks in the subject line.

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4x4Hank · April 28, 2023

On 4/17/2023 at 11:17 AM, Steve Macedo said:

Thank you. I will continue to search. Going to take it in this morning to see if any codes come up.

Was there any diagnosis on your problem? It sounds scary!

Steve Macedo · April 28, 2023

All is good. It's amazing when you change a few words of what you find.

Throttle body in the transmission. There is a service bulletin on this and found it on a different search. Changed throttle body, all fluids, filter and pan gasket/seals. All was accessible from the pan. Reprogramming of the TCM and so far so good.

I was a bit scary to out of the blue to have the rear axles lock up. Really surprised a glad that Noone was close enough behind us and get rear ended.

Thanks for checking