NWI Denali

These LT engines seems to idle rough. I think a lot of it has to do with how low of an rpm they idle at. They almost shake and stumble like a cammed muscle car. I don't know if it's for fuel economy standards or what.

Do you have the 8 speed? If so, it's the tcc shudder. Dealer will do a 20qt flush for you under warranty that should fix the issue. Does it feel like running over rumble strips?

5 yrs ago, the tire selection for 22s was terrible. Now with how many Tahoes, ram limiteds, F150 limiteds, denali's and high countries they sell, there are a ton more options. Good all terrain options too. 275/50 is an oddball size. No idea why GM changed from the 285/45 they used for years. My guess is the get the extra inch of sidewall from 32 to 33. My truck is a K2, and I just put these Cooper Rugged Treks on stock size 285/45. Cooper lists it at 32.36". I absolutely love these tires, I cannot believe how quiet they are for how aggressive of a tread pattern. They have tons of siping for snow too.

Do you know if it's ever been changed? I would do a pan drop and put the new and revised mobil1 atf in and new filter. Then I'd do it probably every 50k from there on out

Do you know if it's ever been changed? I would do a pan drop and put the new and revised mobil1 atf in and new filter. Then I'd do it probably every 50k from there on out

Do you know if it's ever been changed? I would do a pan drop and put the new and revised mobil1 atf in and new filter. Then I'd do it probably every 50k from there on out

Do you know if it's ever been changed? I would do a pan drop and put the new and revised mobil1 atf in and new filter. Then I'd do it probably every 50k from there on out

If it makes you sleep better at night that's fine, but that is Overkill and a complete waste of money.

Well, I finally have a resolution. Had my dealer diagnose it and they actually found the harness rubbed through on the frame near the rear wheel well. Looks like there's a mounting bracket for the brake lines is what did it. They repaired the harness and all good to go now. Thanks to all for the help troubleshooting.

That is the trans shuddering. Since you like the truck, I would have the dealer do the trans flush and see if that fixes it. If it doesn't, then return the truck to Carmax.

The Chevy shake and transmission shudder are 2 different things....

Well, I cleaned that ground and that still didn't do it either. I really am out of ideas at this point. See if the dealer can find anything Wednesday.

What about a tonneau cover or topper?

You are the man, newdude. I know this thread is pretty old now, thank you so much for following up. I ironically have an appt next Wednesday at the dealer, so I will clean that ground this weekend and report back. Are you a gm tech? You seem extremely knowledgeable. Thanks again.