Posts of the Week
The most-reacted posts on GMC AT4 Forum each week — the community's best photos, builds and discussions, ranked by reactions.
Sep 5, 2026
New Owner
Hello, New to the truck world. Always had SUV or a car. Been driving my 2006 Subaru STI since 2006 with a few mods. Just purchased a 2026 2500 AT4 diesel. No mods planned yet...
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New 2025 Canyon AT4x - Left over
hey all, just a little update ... I already tinted the front windows and blacked out the fender flare yellow lights ... bought these -...
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1st GMC.. 2025 Sierra 1500 AT4x
Hello gang., very long time coming.. Had almost a dozen Toyota's and got fed up with their hide and go seek nonsense with their current twin turbo debacle in a 2023 TRD Pro.. Moved into a GMC...
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My solar setup
The biggest thing I’d look at here is the power path. If the refrigerator and Starlink are both DC devices, running them through the Bluetti’s AC inverter and then using an adapter to convert AC...
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Newbie
Just found this forum while looking for info on the trailer TPMS system. Bought new a 2020 HD2500 Duramax that I've had for almost 7 years, 150K on it. Mostly pulling our Airstream and my...
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August 2026 AT4 Truck of the Month Winner: TXAT4X 🏆
The final votes are in! Congratulations to @TXAT4X for winning the August 2026 AT4 of the Month contest with this killer photo from a quail-hunting trip near Big Bend, Texas! 🏆 Check out all the...
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Lets see your CAMPING SETUP!
I live in Live Oak, Florida but for the last two summers I’ve been volunteering in Shoshone National Forest. I had a solar system installed before this summer. I have 1200watts of panels installed...
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Aug 29, 2026
What did you do to your AT4 today?
2inch Front leveling kit with UCA. Mudflap Delete 2inch Hub Centric Spacer 35x12.5x20 Cooper Discover Tires Black American Flag Tonneau Cover. Some trimming required for minor rubbing now it runs like a dream
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Our Admin's...
Avatar is boss. Not trying for brownie points or brown nosing, but he finally put some effort into his profile's avatar, and not just having a "A"!
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Android Auto Won't Connect via Wireless
I have had my 2026 AT4 for about 3 weeks now and it is a constant struggle to get the android auto to connect or consistently connect wirelessly to my phone. I have tried AI...
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GMC AT4 Talk
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Our Admin's...
lol AI? I’ve always thought the admin here was you 🤘🏻 Nah, he's the bar owner, I'm just the bouncer! 🍻
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New GMC Sierra 1500 AT4
First time GMC truck owner here. Recently purchased a 2026 Sierra 1500 AT4 and absolutely love it. Hoping to get the latest updates, news, tips & tricks to keep my truck purring like a kitten.
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GMC AT4 Talk
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From Drive Straight to Off - Is This Okay?
It must be a LD, with it's console shifter? An HD will shut off and a pop-up appears on the dic to, "Shift to Park." It might be a gm feature, but I'd call it a bug. How do you put it into...
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GMC AT4 Talk
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Android Auto Won't Connect via Wireless
That's interesting. Is this different than connecting your cell phone directly to the vehicle's wi-fi? If I connect my phone to my truck's wi-fi, and I don't have a truck data plan, my phone...
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GMC AT4 Talk
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Android Auto Won't Connect via Wireless
I found a problem with the Wi-Fi hotspot, which is required for wireless AA and ACP, that I'm very confident is related to these issues. For some reason the hotspot SSID is randomly being secured...
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2026 1500 AT4 Wheels
I recently purchased a 2026 gmc at4 1500. It has 20" wheels and Bridgestone street tires. I'm not a fan of either and wanted to know if anyone has installed 17" wheels and if they had any...
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GMC AT4 HD Talk
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GMC AT4 HD Talk
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GMC AT4 Talk
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From Drive Straight to Off - Is This Okay?
Pre refresh, 2021 LD with real column shifter ( which is why I went with pre refresh! ) behaves exactly like the HD in this regard. It must be a LD, with it's console shifter? An HD will shut...
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What did you do to your AT4 today?
Anyone install this update? I can see notification in my phone gmc app but no update shows up on the DIC
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DV8 Front Bumper with 3” Elite Pod Lights on GMC Canyon AT4
Hey guys. Hope you’re all doing well. Just got my truck back and had the DV8 front bumper install. Gives the Canyon AT4 a more aggressive look. The fenders had to get cut back. Good quality bumper...
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GMC 1500 AT4 Purchasing
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Any getting a 27
I would always advise against a first year model change. However a new powerplant is enticing, knowing what is under the hood could leave you walking, now.
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Aug 22, 2026
August 2026 AT4 of the Month starts now!
January 2026 near Big Bend, TX for a week of quail hunting. Headed to southeast New Mexico in a few weeks to chase dove.
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New member and AT4 owner
Hi, I would like to introduce myself. My name is Doug and I am new to this forum and a new AT4 owner as well. I just purchased a new 2026 1500 AT4 yesterday with the 3.0...
What did you do to your AT4 today?
Well guys after months and months of debating and researching on this site and others, today I pulled the trigger on tire size and brand. Went with the Toyo AT3 in a 285/60/20 size on my...
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GMC AT4 Talk
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Textured rockers and bumpers
Purchased the truck used and it had a lot of stone rash on the lower rockers. Dealer touched them up and it looked better. Fast forward 6 months and I don’t like the rash touched up look. I’m...
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How big can tires go?
New here, looking for real world experience from people. Completely stock 2025 1500 AT4 LZ0. Came with 275/60R20 tires on the 20x9 silver machined wheels with dark pockets. I will be keeping the...
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New 2025 Canyon AT4x - Left over
As Shorsey says... "Hell yea, Fuck yea!" My last truck years ago was a 2016 GMC Canyon All Terrain - my old favorite truck of all time... got it used and had electrical gremlins in it so I got...
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AC plugs not working
I have a 2022 AT4 crewcab 6.6 liter 2500. The plug in the bed and the plug in the cab or not working. I am able to push the power button on and it does light up but there is no power going to the...
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Spark plug change 2021 AT4
.3 miles per gallon isn’t a significant enough difference to be meaningful. I’m not poopooing your win, but it’s scientifically insignificant to the point that it’s not worth the mention. As...
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S&B 75-5128-1D air intake kit with supercharger compatibility issues
I would start with some kind of a tune or pedal commander type device before you go out dumping thousands of dollars into a supercharger to throw on top of an already unreliable GM v8. Especially...
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A Formal Concern Regarding the GMC 1500 AT4 Warning System
Dear General Motors Corporation, I absolutely love my GMC 1500 AT4. It’s powerful, comfortable, sharp-looking, and probably one of the best trucks I’ve ever owned. Unfortunately, I may have to...
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GMC AT4 Talk
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Android Auto Won't Connect via Wireless
This is also an issue with wireless carplay. I bought my truck a month ago and my carplay connects maybe 10% of the time. I took in to the dealer last week and they said they updated the...
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Android Auto Won't Connect via Wireless
I have been having the carplay connection issue since the last update. I changed the "fast start up" to off, and it connects most times. The last time it didn't connect, I went to the apps and...
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1015 diesel fuel filter
I upgraded to the VSE fuel filter system. It was a little bit difficult stuffing it in with the TITAN 56 gal tank but I have way more confidence with this two filter system system over the small...
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Aug 15, 2026
New custom fender badges
He's really great to work with. Did mine for the 3.0 Duramax and then remade for the trade.
New 2025 Canyon AT4x - Left over
As Shorsey says... "Hell yea, Fuck yea!" My last truck years ago was a 2016 GMC Canyon All Terrain - my old favorite truck of all time... got it used and had electrical...
GMC AT4 HD Introductions
New From South Texas
I’m running Bilstiens too. I have a longbed 3500 and you can really tell that these shocks are superior to what they come with. Both hauling and empty…..
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New guy here
I just picked up my first AT4. The other GMC pickups I had were the elevation I LOVE this truck !! Not sure what mods I’ll be doing but I’m sure I’ll get some great ideas from everyone else on...
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GMC 1500 AT4 Talk
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What did you do to your AT4 today?
This is the first step in finding a new home for my truck; no! I’m not selling my truck but as several of you may be aware, we are selling our home in view to relocating to Las Vegas, NV to be...
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Won’t Detect New Brake Pads/Pad Monitor
Just to give a quick update, I had to buy a scanner to clear the DTC and now I have no issues. Front brake pads show 48% and the rears at 100% as they should be. Thanks to all that responded and...
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What did you do to your AT4 today?
Went to the truck stop and filled my def. It was down to 1 bar on the dash. I honestly forget about it most of the time since it doesn't use much at all. Actually, my wife was the one to remind...
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GMC AT4 Introductions
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New 2025 Canyon AT4x - Left over
I need to go check my whiskey stash; seems like @gemarsh may have drunk it all
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GMC AT4 Introductions
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New 2025 Canyon AT4x - Left over
I need to go check my whiskey stash; seems like @gemarsh may have drunk it all Seriously though, short people are 'more down to earth'! 🤣
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GMC AT4 Introductions
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New 2025 Canyon AT4x - Left over
I'm getting more down to earth :ROFLMAO:. I used to be a smidge over 6' tall and I've shrunk to 5' 9" and probably shrinking more. My problem is I'm growing horizontal.
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GMC AT4 Talk
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Loose leaf spring U-bolts (TSB 19-NA-129)
Did they do it under that bulletin? I don't think so since mine were replaced long before the bulletin; I kept pestering them until the second or third visit, a tech listened below with a...
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Camshaft/Lifters?
I mean it's possible, no one here is going to be able to diagnose it over forums. If you aren't happy with their diagnostic and you're under warranty - different dealer. If not, any competent...
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2024 Sierra 1500 AT4 3.0
New to the forum but have been researching here since I picked up my ride in January 2024. S&B cold air intake. Smart Cap topper. Banks A pillar module idash M&R Front grill light bars Frontrunner...
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Aug 8, 2026
July 2026 AT4 Truck of the Month Winner: TheShark 🏆
A huge congratulations to @TheShark, our July 2026 AT4 of the Month winner! This killer shot captures some impressive suspension articulation and a great day on the trails in New Hampshire with Ridgeback Guide Service. 🏆 Check out all...
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What did you do to your AT4 today?
Finally got around to installing my onboard air
Pistol Mounts
Being a South Paw, I was needing a solution for the left side of our truck. I found a custom door pouch 'organizer' from Door-Daddy. They have an insert for the front cup...
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(2) PPE LM2/LZ0 oil pans, red recovery hooks, Boost Auto dome light
Here are two terrible quick ones. We also did a family photo before my wife traded hers in. All diesel, and all GM. Daughter, wife, me (son drives a Honda and therefore wasn't invited).
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AT4 of the Month Winners
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July 2026 AT4 Truck of the Month Winner: TheShark 🏆
Thanks for the kind words and the votes! I have been trying since I joined the forum and the win feels good😎 Edit: that new big red badge looks great too!
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August 2026 AT4 of the Month starts now!
The August AT4 Forum Photo Contest is officially live! Whether you roll in a Sierra, HD, Canyon, or Yukon, this is your chance to show off your rig and claim Truck of the Month bragging rights...
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Cascading codes all of a sudden
Turned out to be a bad fuse block above battery and right front wheel speed sensor.
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AT4 of the Month Winners
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July 2026 AT4 Truck of the Month Winner: TheShark 🏆
Thanks for the kind words and the votes! I have been trying since I joined the forum and the win feels good😎 Edit: that new big red badge looks great too! Your raising the bar for future entries!
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GMC AT4 Introductions
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2026 Canyon AT4 Nightfall Edition
Welcome. What is all included in the nightfall package? I see black badges, sportbar and running boards. 20" Machine faced/dark pocket aluminum wheels, rocker panels (not running boards)...
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AT4 of the Month Winners
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July 2026 AT4 Truck of the Month Winner: TheShark 🏆
I really wish the truck had full lockers but they didn't offer them until the AT4 X released. Great footage of me having to spin the rear to get it to lock
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GMC AT4 Introductions
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Hello from WA
Snohomish area Welcome! I also have black 2026 at4x diesel in Seattle, also purchased in Boise 🥳
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AT4 of the Month Winners
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Knocking drivers seat + lying technicians!
Drivers seat makes a knocking noise that is also felt in the seat when turning left to right, no movement front to back. Problem since I got the truck, took it to the dealer at...
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Aug 1, 2026
Lets see your CAMPING SETUP!
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Building My Weekend Adventure Rig
I finally had a free Saturday and tackled onboard air. I ended up putting a generic ARB-style twin compressor behind the passenger side fender using the bracket that came...
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New Member
Picked up a 2025 GMC Sierra 1500 AT4 in Onyx Black here in Oklahoma with just 20,000 miles. It's the 3.0L Duramax, and it's bone stock...for now. I'm trying to decide between adding a level kit...
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Welcome to AT4forum.com - Introduce yourself!
Good morning! Just purchased a nice used 2024 GMC AT4X Sierra 1500 with the 3.0 Duramax. I had one similar a few years back in the regular AT4, and then a Canyon AT4 after that had to get rid of...
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New AT4X owner
Just traded my 23 Colorado ZR2 for a 26 Sierra AT4X and absolutely couldn't be happier to be back in a fullsize. Had a 2014 Sierra before the Colorado and thought the smaller truck would work.
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July 2026 AT4 of the Month starts now!
2026 3500 AT4, upgraded wheels, black package. Had it 7 days now.
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2027 GMC Sierra 1500 Full Press Release: New Features, Engines, Technology & Changes
What engine did it have in it? Looks like the 3.0 by the plug on the front bumper? And how did you have one available to drive? Thought they're still months out... If you live near the proving...
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New Memeber
Hello, My Name is Aaron. Thanks for allowing me to be a part of this group. A little bit about myself. I own a company that builds emergency vehicles for state, local, & federal agencies in...
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GMC AT4 HD Problems and Issues
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GMC 1500 AT4X
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MultiPro Tailgate Real World Usage
MultiPro Tailgate Real World Usage: Works great for those sporting event tailgates!! The Kicker set up is always a hit!! I use that step during tailgating to set the TV and use the speakers as a...
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GMC AT4 HD Problems and Issues
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No Sound from infotainment center or turn signals... HELP (Resolved)
So after 13 months of owning my truck I am still having issues at startup with no audio. Wednesday I spoke with the owner who actually took the time to talk to me and I showed him the PIT bulletin...
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Jul 25, 2026
2027 GMC Sierra 1500 Full Press Release: New Features, Engines, Technology & Changes
Just got to check one out today. Thing sounds gorgeous. Its burbles and has a baja mode. Im in love.
MultiPro Tailgate Real World Usage
MultiPro Tailgate Real World Usage: Works great for those sporting event tailgates!! The Kicker set up is always a hit!!
I'm a new member with a 2024 GMC Sierra 2500hd AT4 coming from a 2022 Ford Raptor.
Glad to be here. Hope everyone is doing great! I have the Max towing option which from what I'm told pretty much has the 1 ton diffs and suspension. anyone got any thoughts on...
First diesel
Hey yall, my name is Tyler and this is my first newer truck and first diesel. The wife and I decided on a 2024 2500 AT4X HD with the 6.6 Duramax. Thunderstorm Grey, awesome rig! We live in...
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GMC 1500 AT4 6.2L V8 engine
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New Intake from North American Performance
Just my 2cents, but adding a cold air intake doesn’t help much. If you increase air intake you’re still limited to how much air is leaving (exhaust). Additionally, today’s trucks have fine...
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GMC AT4 HD Modifications
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Seat covers
I understand this is an older post, but I’m curious about the gear you outfitted on your truck. Specifically the Baja Designs lites. You wrote “CarPlay and voice controlled” next to it. The lites...
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Android Auto Won't Connect via Wireless
Got my truck last Saturday and immediately left on a week long work trip Sunday. It was hit or miss for connection the entire time and randomly although showing the phone connected and on a call...
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Well, I got my first one!
If it just the clear coat, buy some touch up clear coat. Apply a very small amount ( one very very small drip that just barely fills the chip. Then walk away for 24 hours. Then check it. If the...
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AT4X - AMP Research Steps
Have had mine for over 2y and the finish on both of them are coming off. They replaced one under warranty. I haven’t filed a claim for the second one. This is the step surface on one boards. This...
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Hello, new Canyon AT4X owner
New here. Hoping to learn and get some more performance or other upgrade tips for my 24 Canyon AT4X. Just got it about 2 months ago. Found this site, did a little poking around and felt like...
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2500 AT4X or.......
I suggest test driving everything and not relying on forum opinion on what's better or worse. What I like might not be what you like or need etc, unless you're looking for mechanical opinions - I...
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Hello from WA
Hello all, Just joining to hopefully learn and share about my new 2026 GMC Sierra 1500 AT4X Duramax. Decided on onyx black and will be picking it up this Saturday (7/25) after a trip to Boise...
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GMC AT4X HD
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2500 AT4X or.......
I think they all have their issues and you can get luckily or screwed. I have very much enjoyed my 2024 AT4X HD gasser however. Did not need diesel power but needed the payload and longer bed...
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New Intake from North American Performance
This thing is still bouncing around in my head. I’m fighting the YOLO justification and the sensible adult with more important things to do with $600 (I mean, I really want one of the gen 6...
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Jul 18, 2026
July 2026 AT4 of the Month starts now!
Showing off some suspension articulation and having a great time on a trail run in NH with Ridgeback Guide Service. AT4 earning it's badge.
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Just got the C8 push to start...
Button delivered. Supposedly adding a corvette push to start button adds 29 horsepower to the Duramax! 🤣 We'll see. Kinda think it's over hyped like cai's. Anyway, it feels...
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GMC 1500 AT4 Talk
Why I no longer own an AT4...
Wish you luck. It's almost a crapshot anymore. Kinda thinking @Truebee might have had it right. Put 40-60k into a squarebody and have something up to date and dependable, with...
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New Intake from North American Performance
I'm a classic truck lover, have a '72 C10 stepside (has a '69 grill). But this is a little tacky to me, luckily you don't open your hood often and have to keep seeing it. I think it would get old...
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GMC AT4 Talk
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Android Auto Won't Connect via Wireless
I too had Wireless AA issues. My solution for now was to go into the settings on the truck and turn off "Fast Start up". It basically forces the infotainment system to reboot each time you start...
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2024 Sierra AT4 3.0 Build
I am honestly a bit surprised at the lack of threads in this section. This is an absolutely perfect way to document what you have done so far and bounce ideas off others for future modifications...
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New splash guard
I got rid of the plastic splash guard and replaced it with a WC Fab aluminum one
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New 2026AT4 Level
Looking for advice on de-raking, ride quality, and tire size on my 2026 Sierra 2500HD AT4 Duramax I recently picked up a 2026 Sierra 2500HD AT4 Duramax with the Max Trailering Package, and I’m...
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GMC 1500 AT4 6.2L V8 engine
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New Intake from North American Performance
I'm a classic truck lover, have a '72 C10 stepside (has a '69 grill). But this is a little tacky to me, luckily you don't open your hood often and have to keep seeing it. I think it would get old...
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GMC 1500 AT4 Talk
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Engines - How many have the Duramax?
So learn me something, fuel shows up in oil on diesel engines? Most definitely. Diesel requires heat to ignite, ie, high compression. Diesels will "slobber" on cold starts. And unlike a gasser...
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GMC 1500 AT4 Photos & Videos
12
Airhorn Installation - Thoughts
got it installed (only $250) so cost me around $1300 in all loud as hell probably not practical but fun
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Hello AT4 Forum! 👋
Welcome.. how about a direct replacement fog light upgrade for the 2022.5 and up. I have a 2022.5 AT4x and there really are no good options to upgrade the stock fogs.
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Hello all!
Just an introduction, I currently have a ZR2 Bison. I flop back and forth between GMC and Chevy over the years. Could not get a cardinal red AT4X so had to go Red Hot Bison this time. Look forward...
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GMC AT4 Camping & Traveling
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Lets see your CAMPING SETUP!
Here we are at Brooke Lake in the Bridger Tetons outside of Dubois, WY. Might have to change my profile pic. Think GMC would let me be a location scout for their photo shoots? Or is AI going to...
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