New to the forum, anyone else have this issue?

Cross88 · September 5, 2020

Hello everyone, new to the forum, I’ve got a crew cab 2wd ltz 6.6 gas. Was wondering if anyone else has had an issue with their transmission, specifically the 2-1 downshift. Mine seems to shift pretty rough most time. Haven’t taken it in yet, been putting it off cuz I need the truck. Trucks purpose is daily driver and tow pig. I have a fifth wheel, but it’s only about 50% of the trucks capacity. Any thoughts, advice? Thank you

2020_3500HD · September 5, 2020

I have had it a few time but only during extremely hard braking, my 09 2500 with the 6l90 would do the same and got 250,000 trouble free miles from it.

Cross88 · September 5, 2020

Well that’s good, hopefully I’m trouble free for a long while also. It doesn’t do it all the time, and sometimes it’s worse than others. So who knows. I have less than 4K on it now. Here’s to hoping it figures itself out.

Stand By · September 7, 2020

I've had it a few times slowing quickly while turning. Feels like a normal gm transmission characteristic to me.

SteveSr · May 20, 2021

I have a 2021 2500 HD with a 6.6 gasoline as I am coasting up slight inclines with my foot off of the accelerator as it down shifts sometimes I get a loud clunk I don't like it either but haven't took it in yet

millews · April 4, 2022

On 5/20/2021 at 2:08 PM, SteveSr said:

I have a 2021 2500 HD with a 6.6 gasoline as I am coasting up slight inclines with my foot off of the accelerator as it down shifts sometimes I get a loud clunk I don't like it either but haven't took it in yet

Did you ever get this resolved? I have been dealing with the same issue for months. I am taking back to dealer tomorrow and will drive to show and feel he problem. You literally have scream at them to fix warranty issues.

Ray Pickle · April 5, 2022

Without experiencing your truck's specific symptoms its hard to ascertain if it is normal drivetrain "slop". I will say that the length of driveline and rear diff setup will cause a minor clunk under certain downshift parameters. I notice it is most consistent slowing and turning as someone else has already mentioned.