MrLeadFoot

Exactly!

I understand completely. And, you're right, they don't care one bit! If they did, they would fix our shaking and vibration issues, as well as do the right thing on the engine disaster. And, being that these trucks are so darned expensive, they really should take care of their customers. Seems like the older models ran smoother and their engines lasted forever! I'm with you, and won't buy another one of these trucks, that's for sure.

Wait, I thought they did everything right by you? What was the problem with the rental and the handling of things that you speak about?

Hey Kevin, good to hear you're still on this thread. Regarding the reduction, are you sure you've not just gotten a little more "used to it"? I have 39k now on my 22.5, and the shake hasn't changed, but I've come to be more accepting of it, so to speak. BTW, can you do me a favor? When driving, I put my hand up on the upper rear corner of the driver's door, where it meets the cab, and feel vibration between the door and the frame. Not a gap, per se, and certainly no wind noise. Do you feel that, too? Just wondering if all doors do that, kind of like the little play in the tailgate when shut. And, if they all do that maybe the culmination of it all contributes to the vibration we all feel, because it would have to be a high wind on all those parts before we feel it, and why we don't feel it until freeway speeds. I also notice if there is a strong crosswind, I don't feel the shake nearly as much, so wondering it it might be just shoddy tolerances everywhere. Hope that makes sense. Yes, I am reaching here!

While leveling kits can cause issues, your leveling kit is not causing this issue. I've been through 3 different dealerships, 2 GMC, 1 Chevrolet, at the recommendation of the case manager at GM itself, and they all went through the same gyrations, until a GM field tech was finally called in to do what they do best: Stamp the case as being "normal for this type of vehicle", seemingly to try to setup a legal defense. If it was "normal" why did they have me go to 3 dealerships and have a field tech come out? FWIW, the service manager at the Chevy dealership personally inspected the shocks to ensure something wasn't stuck up under their "sleeves", too, because he was puzzled by it. But, once the field tech came out, the service manager's hands were tied. I have two sets of OEM Denali wheels. Stock 22" and 20" with stock tires. Although the vibration is still there with the 20s on the truck, it's a little less noticeable so I run the 20s for the dry season. Because the stock 22" tires are way better for wet conditions than the pseudo-AT stock tires on the 20s, I suffer the more noticeable vibrations and run the 22s for the wet season. I'm a little more fortunate than the next guy, I think, because mine vibrates between 68 - 81mph, so I tend to drive at least 84 mph on freeways, true to my forum username. While I'm living with this vibration for now, I will never buy a GM 1500 truck again. None of my friends with 2500s have this issue. Even so, if I ever buy any GM product again, it won't be without being able to take the exact vehicle I would buy for an overnight demo, so I can put it through its paces. Regarding ARC, ARC seems to cause fast vibrations, like reveberations, when you encounter little road imperfections. I'm sure you experience it, because when I was test driving models, I noticed that all ARC-equipped models did this, regardless of engine model. The WT and AT4 models I drove did not do this. But, at the time, I did not notice the high-speed vibration, and I wanted a truck that with the best handling and ride, which is why I went with the Denali. But, I think other people who posted on these threads have non-ARC vehicles, so I stopped chasing the theory of it being ARC-related.

Is the ride a little stiffer, too?

There goes my theory that it might be a wind vibration, given you have the 2" lift, and I thought it might be wind going under the "normal" height models. That said, I have noticed that if I put my fingers in the area between the door and body while driving, I can feel the slop between the two pieces as they move around inependently of each other. Not enough to let wind in, but I can't help but wonder if all the body parts have that much tolerance, could the vibration be from these parts shifting around? My son's and daughter's Hondas don't have this much play, and neither does my wife's Mazda CX5. I also don't recall my Suburban being like that either, and it didn't vibrate like this truck. It is entirely possible that all the trucks have a wider tolerance and thereby vibrate because they simply didn't make them as tight as their other vehicles. I've been trying to find someone with a Tundra that I can ride in and see how they are but I would venture to guess they are tight and smooth.

I thought they possibly changed the oil spec for the new engine. Glad they at least handled the replacement for you promptly, given the circumstances. Good luck with the new engine.

What oil are they recommending for your replacement, 0w20?

Now we're talkin'! https://gmauthority.com/blog/2026/01/nhtsa-investigating-post-recall-gm-6-2l-l87-engine-failures/amp/

Yeah, I saw that one, too, a while back. I thought this would be the last truck I would buy. Looks like it will instead be the last GM truck, sepcially since they are also pushing to sell vehicles that we also have to have subscriptions for to enjoy all its features.

Figures! Just curious if, regardless of what plant at which a truck was built, it will have those bad parts of which you speak?

Wow, Bear is bigger than most Belgian Malligators, and rivals German Shepherds! Sorry, didn't mean to jack my own thread!

Is that a typo? I ask, because as a professional dog trainer for 40 years, I've done everything from patrol dogs to service dogs to family dogs, worked with thousands of dogs across all breeds and sizes from Yorkies to Malinois to Mastiffs to Russian Ovcharkas, and I've never encountered any Aussies that heavy. Then again, you could have world record holders. Just curious.

Is the bottom, where it extends past the bench, strong enough to hold a German Shepherd? Or, would I need to add upright supports? I also wish they made them so they cover the backseat headrests and go up the back of the front headrests. I guess I can probably make something for the back of the front headrests myself, if necessary.

Are any of you running 5w40? Why, or why not?

So, are you saying GM does not specifically say in the recall we need to run Dexos R, and only need to something that's 0w40? I ask, because, for some reason, I never got the insert, only the cap, so I don't know if the insert specifies Dexos R, or even a specific formula like SuperCar for that matter. I can only go by what I see posted on the internet, and you know how that is. Since you're at a franchise dealership, I trust that you have access to the official standing on what oil they are spec'ing.

Thanks for that. Now to the real question at hand, can you please clarify exactly what GM is recommending? Is it wny 0w40 oil that is DEXOS R, or do they specify an exact formula? For example, can we use ANY of the ones listed that GetGone pointed to?

Show me where I doubted you. I merely asked for clarification because I came across something earlier where the European formula did not say it met the DEXOS R spec. In either case, thank you for posting that supporting chart, in the end, confirming what you said earlier. You might want to go get checked out, because your tendency to fly off the handle so quickly is really not good for your health.

This is literally what you wrote: "The 0W40 is new Dex OS R spec in SuperCar oil and their website states all grades of 0W40 meet Dex OS R." I had previously come across information on their site that showed not all their 0w40 weights are Dexos R, so I respectfully asked you for clarity, but you didn't respond. I was not arguing with you. In fact, I even said in a later post that if what you found was true, and all their 0w40 weight were indeed Dexos R, it would be easier to source oil for our trucks locally. But, after I mentioned your quote to someone else, you jump in screaming and yelling? Why are you so always so defensive, and antagonistic? Are you ok? Feel free to ignore my posts. Sheesh.

If you read GetGone's post again, he said " their website states all grades of 0W40 meet Dex OS R", which goes against what I found. You are pointing to the Supercar formula which, of course, does meet the DEXOS R spec. If all other formulas in 0w40 do indeed meet the DEXOS R spec, I want to know, because if that's true, it makes it so much easier to source locally. On the other hand, if they do NOT ALL meet that spec, someone could get the wrong oil, so just trying to get clarity on what GetGone found (unless it was simply a typo, which happens).

Not sure if you have a typo in your post or not, but where did you read that ALL of their 0w40 oils meet the R spec? While that would sure make it less confusing, this page on the Mobil 1 site shows that not all 0w40 meet that spec. https://www.mobil.com/en/lubricants/for-personal-vehicles/our-products/motor-oils/mobil-0w-40-viscosity-oils#f:@marketpagesearchfacets=[0W-40]

DOUBLE POST, please delete.

Oops my bad. I must have mis-read something. Thanks for the correction.

Thanks for the Amazon link. That's actually cheaper than the Amsoil stuff, and the Amsoil doesn't meet the Dexos R designation, either. The only problem with the Mobil 1 on Amazon is that they sell 6 qts. at a time, when we need 8 qts.