richmz

It's important to know what you're measurement reference is. Are you measuring from.. Top of tire to center of wheel well? Ground to bumper? Ground to frame? Most pickups are higher at rear by design so that when loaded it will distribute the weight properly. Here is a '21 GM AT4 file photo. The rear rake is noticeable, probably about what you're seeing. Last year I took some photos of mine on level ground when loaded with over 20 bags of bark mulch. I was impressed with it's stance with it loaded, likely around 1,000 lbs or more. It handled fine at speed too.

Nice rig towing that 7,000 lb beauty. I have the same rig in Pacific Blue. Two weeks ago got a call from a nearby friend at 5 PM whose Corvette broke down immediately after a fuel stop in Georgia, about 225 miles from home here in Florida. The shifter cable broke when going into gear to leave. Loaded tools and floor jack and hooked up my 23' Continental enclosed car trailer. This was the first time I hauled it with my PB '20 AT4. Hauled many times with my c06 5.3L Silverado, which did the job but struggled. The AT4 pulled it superbly, empty around 3500, about 7500 with the Corvette loaded in, including its full fuel tank and a fully loaded trunk. Long night. Got there at 10 PM, got food, loaded the car then took off after midnite headed home. Arrived 5AM safe and sound, albeit enroute to GA, that one rogue orange rubber cone I hit when next to a 18 wheeler with nowhere to go in late night road construction. Truck got no damage but the trailer got it in the face and wheel well after it flew out behind the truck. .......

Got a call from a friend at 4:30 pm Wednesday that his 2011 Corvette broke down at a gas station in Georgia after his last fill-up for his drive, about 250 miles from home here in eastern/central Florida. He had been up since 2AM driving from MD, and also after getting stuck on Rte 95S for several hours of road construction in NC. I told him I'd rescue him. I own a 2004 20'/24'(OAL) enclosed Continental car trailer. Great trailer with lots of capacity, winch, etc. I hadn't used my AT4 to haul this one before the call. My 2006 Silverado 1500 4x4 5.3L had plenty of pulls but always struggled. When I left at 6PM after emptying the Continental of misc stuff and hooking up my weight distribution hitch, loading floor jack, tools etc, I got on Rte 95N for the ~4 hr drive. The AT4 is a beast. It pulled flawlessly and much better than the old Silverado. At about 9PM I was in a construction zone down to 2 lanes. Had a slow 18 wheeler in front so I got in the left lane to cautiously pass. Speed about 50 or so. Left lane closed off and cones were along the white lines, but it was impossible to avoid one cone that had fallen over right in the path of my left front tire since the 18 wheeler was right next to me. Bang! I heard that thing hit 3 or 4 times under my rig. I pulled off the next exit to a parking lot to asses the damage to my truck. Looked everywhere and underneath for and damaged lines or wires etc. Luckily the AT4 had none. But the trailer caught that nasty cone flying out the back of the truck, denting the diamond plate fascia, then under the trailer tires, hitting the side wheel well trim and kicking the rear lip out. Fortunately no other issues. Got back on the highway for the rest of the trip. I arrived in GA at 10:15PM. I had to jack up the Corvette rear end to get under it to manually put it in neutral. His shifter cable broke so it was immobile. We winched the Corvette into the rig, ballparked it's position for best tongue weight, tied it all down and off we went at around midnight. I got back home at about 5:30AM after dropping him off at his house. I'll be fixing it for him as I have a lift. It was a long day for us both. The AT4 pulled the loaded trailer just like it felt empty. Total weight about 7500 lbs. Not great shots from the side but here it is. Rich

Yes the old iron block 5.3L Vortec was ok and a better choice over the base(4.6L iirc?) at the time. I've read about the present aluminum block Ecotec3 5.3L version being more powerful. My '06 was 4WD so it likely dropped the tow capacity down a bit due to added weight . It had the HD Trailer Tow pkg. Not sure if that actually adds weight or not, or is a wash for the tow capacity. I'd imagine the same with the AT4 being 4WD that they drop it down a bit from a 6.2L base rig in 2WD. The 6.2 is likely a bit heavier than the 5.3 but probably not too much. Is yours 4WD? If so then maybe as you said the GMC flavor may be a few hundred pounds heavier and they have to drop the tow rating to compensate. Rich

It's the AT4... 6.2L gas with 10 speed. Pulls like a dream. Trailer weighs only around 4,000 lbs plus the water tank was full, so maybe 4400 or so, but when we go off fully loaded with stuff it'll likely be around 5k. No Gray or Black water in it when I test drove my setup after they delivered it. The trailer rating for the truck is 9,200 lbs. I have a load leveling hitch setup and set it so the truck is within about 1/4" or so from the unloaded level position. No squatting. IIRC when I first connected up it only squatted about 1 1/2" at the rear bumper which surprised me. After I set the torsion bars to raise it it came right into it and leveled off nicely. I had a '06 Silverado(5.3L, 4 Spd auto) for 15 years and towed my 23' Continental enclosed car trailer(cars were about 3,500 lbs, total about 7,000 lbs) and it always struggled and I always had to drive in D3. The '06 was rated about 7,500 so I was using all of it. Night and day between the 2. That's why I upgraded to the 6.2L, knowing I'd be better off, but didn't want to go the HD 2500 route or get into a diesel. Rich PS the last 3 photos..... I had 23 bags of bark mulch loaded in the bed when I took those photos. I was amazed how it held up. When I drove back from HD all loaded up it felt great. Amazing truck.

Ready for some travelling soon. Forest RIver Salem Cruise Lite 17'. Added the GM trailer camera system too. A few camera views here..... Default view from side mirrors https://www.youtube.com/watch?v=zhMS11KDJQU Transparent Trailer Cam view https://www.youtube.com/watch?v=eiTgTIGAqFw

Haven't..... but doesn't mean it hasn't to others. Did you try repeated on-offs and wait to retries? Regardless, you need that update to correct related radio issues so it may be best to have your dealer do it so there's a record of the fault. They can also diagnose the wheel button functions as well, if it persists. Please let us know what happens. Rich

Update... Wednesday I setup an appointment for 1st oil/rotate and to address and record the radio sound issue I had, and the HUD display loss, both of which were only once. A new oddity had been occurring too when XM would just cut out on engine start. It would display "acquiring signal" but never would in known good signal areas. The XM "acquiring signal" fault had continued intermittently over the last week. Continued "resets" by power off/on or engine off/on would not correct. Typically after a few hours of rest and restarts, XM would return. Ironically GM-Trucks.com sent me a email Weds night and included this..... GM Releases Significant Over The Air Update For 2020 Silverado/Sierra & Other Vehicles When I arrived yesterday morning for the service I told the Service Manager about the update. He said he hadn't received it yet and even mentioned...."We often find out last..." I gave him the Update Ref#, 20-NA-199. The update includes s/w corrections to both the radio/display and the XM "acquiring signal" issue. The Service tech applied this 20-NA-199 update to mine. Everything fine so far and will update if any issues. Rich

My 'just acquired 20 AT4 after 3k miles just did that... No radio/GPS lady sound after sub freezing temps Saturday morning. Just started out long drive back south. Disappointed, but..... Then after a while sound returned. Very strange. At first I thought maybe a built in delay due to low temperature but not sensible to engineer that in vehicles that reside in cold climates. It must be a hw or sw fault, albeit intermittent. Then after another stop and restart, the HUD disappeared. Later after another shut down and restart, HUD display reappeared. Drove 1500 miles more and neither the radio/GPS lady sound or the HUD malfunctioned. All ok. Appt will be setup at dealer to see if they can get any failure codes or if a TSB exists. Need 1st oil change after 4k miles in 3 weeks anyway. Oil life around 25% but I want it done now. Truck was awesome for the trip. Sadly for family illness needs, but all ok now. I'll follow up with info. Rich