Atlas

You may try having them professionally aimed. You came here to ask the question, so people are giving you answers. People are flashing you for a reason. They think your brights may be on, or your headlamps are not aimed safely. It's not offensive, unless they leave them on. If you're over 30, you'll understand that really bright lights from oncoming traffic are annoying, and can make for unsafe travel.

It sounds like they're not aimed correctly. You might want to double check how you're aiming them. Probably not a great idea to flash back if your beams are already too high, plus you're adding fogs and mirror lights. It's not a war, and headlamps shouldn't be used offensively.

Beware of "free" service. Back when the Duramax 2.8 was new (Colorado/Canyon pickups and some vans), dealerships routinely filled them with bulk oil that doesn't necessarily meet the spec outlined in the owner's manual. The 2.8 required a Dexos2 oil, one of the important parts being the oil is specified to be ACEA-C3, having low ash content to get the expected service life out of the DPF. Dealers would put whatever 5w30 stock they had into these engines and most owners were none the wiser. I always adhered to the spec on mine, and once needed to buy the correct Dexos2 oil from the dealership. Gave them year, make, model, engine, and the parts guy comes back with 5w30 Dexos1. Nope, I said, that's not right. He clicked around in the computer and wrote down a different part number. I only needed 2 quarts, and that's all he had in stock. Casually, I asked what they use for service fills on these trucks, and he replied we use Mobil 1 here for synthetic, 5w30 all comes out of the same bulk stock we use in all the vehicles that specify it. Huh. Turns out, that's not unique. Lots of 2.8 guys see on their invoices bulk oil fill or the wrong spec being used. Point is....if you take that new Duramax to a chevy dealer for "free" service, make absolutely darn sure they're using the correct spec (Dexos D, now?) and document it if there's ever a warranty issue.

Auto start/stop has been in use longer than that, and Buick certainly wasn't the first in the world to use it. Better yet, why don't you produce evidence that I'm wrong, since you're refuting the claim. This thread wasn't meant to be an argument about auto start/stop technology, but since you've dug in, go ahead.

The pisser about the DFM credit is that the functionality isn't there, but the hardware is. You still have stupid-complex hardware in the heads of your engine but no way to control it. 100% unlikely that GM will ever retrofit the non-DFM trucks with the electronics required to use it. So, you're accepting all of the risk of that extra hardware with no return on the money you spent on it, save for a $50.00 credit. Auto start/stop is a joke. It might save a cup of fuel over 100 miles. Meanwhile tearing up a starter, dirtying the oil, and destroying batteries faster.

If it's a typical emissions check, it involves driving the car into a service bay. Some put the car on rollers, others just have you hold the rpm at a specified speed for a couple of seconds while sensors and sniffers take readings. They'll need to plug into the OBD port and do visual checks. Not a big deal. I'd do it if I owned one. $100 bucks for a few minutes of time, bonus if I got to see the actual readings and how they compare.

A little of this, a little of that. OP has every right to be upset that GM over-stated, over-sold the tow capacity and then later revised it after he had purchased the truck. That's not good for GM, and it's not good for the customer, certainly without any statement or offer of compensation or remedy. In hindsight, maybe it wasn't the truck for the job, even if barely inside of the stated capacities. Personally, if I were to tow something of significant weight, regularly, I would err on the side of "too much truck" versus having to worry about being technically and legally overloaded if I have too many personal effects in my travel trailer. Whether for reasons of budget, frugality, or inexperience, the truck was purchased with maximum capacity in mind and GM has put him in an unfortunate situation. Tell us about what GM does for you, would be curious how they plan to work with their customers.

Update: Yeah, that didn't fix it. I've turned off the reminder/alert to see if I can just get the thing to shut up. But that doesn't stop the truck's confusion about the fob location when I'm in/out of the truck or need to leave it running. This is over-complicated and unnecessary technology IMO. Not a boomer, just a 40 year old who does technology for a living, continually asking, "who actually needs this ******?!" Things in vehicles designed to "aid" in the operation and driving of a vehicle are actually more complicated than the acts of operating and driving themselves, something I'm hesitant to describe as "progress". I'll get off my soapbox now, for anyone who remembers wtf a soapbox is, it was actually before my time too, but it was the ancient equivalent of youtube/tiktok whereby someone broadcasted to the world their opinions and judgements, whether anyone actually wanted to hear them, or not.

I basically did except for a few miles of the first 500. It was pretty easy - just planned to get stuck in traffic and take back roads everywhere. That equated to lots of gradual acceleration, shifting, stopping and "break-in" exercise. Starting at about 600 miles I took my first longer trip of about 250 miles at speeds 60+ and over a few mountain passes where the 5.3 got to breathe heavy. Not all trucks get a break-in. Rentals, fleet, work trucks usually don't. They still last hundreds of thousands of miles. But this is a personal vehicle for me, and I had the time/space to drive it according to the book, so why not.

My buddy has NBM Trail Boss with some extras to make it really aggressive-looking and sounding. I went the opposite direction and bought mine as a total dad-build. I wanted a comfortable truck for the highway and that's exactly what this is, column-shift, bench seat, chrome bumpers, highway tires and all. I think I kinda like it. IMG_8200.HEIC

TFL is a good real-world test for the average person who mashes the pedal and doesn't care. Something happened. My bet is on low speeds and inadequate air flow. These trucks don't come with mechanical fans and I haven't found any good information about the transmission cooler, where it's at or if it even has one. GM should pay attention because this is how the general driving population will use their trucks when they have heavy loads. So, on this one... .....I'm a have to say no. 4-low isn't appropriate here. It's appropriate when you can't keep fans and fluids circulating fast enough while locked out in 1st gear, as well as sticky off-road situations where it's better to have at least one drive wheel front and rear turning. The truck should be able to turn enough RPM in 1st, 2nd, 3rd for the conditions described in the video. Perhaps locking it into 2nd or 3rd would have helped to eliminate unwanted upshifts. I've spent a fair amount of time off-road in the last 20 years...4-low (or hi) isn't really something we ever use on dry pavement, and generally not above 15-20mph. Not if locking out first or 2nd in 2 or 4hi provides enough power and cooling.

Easiest way to find out what axle you have (GM or AAM) is to email [email protected] and request a build sheet which will show all RPO's and supplier codes included with your truck from the factory. Make sure to include your VIN. I did this just a few weeks ago and the response was within an hour. As noted above, you'll see supplier codes on the sheet for which axle was supplied with your truck, SU5, SU8, etc. Then you can look up in the maintenance thread in this forum which fluid applies to your axle based on the supplier code. Surprisingly, there are different fluids spec'd between the various axles. If you're going to pull the diff covers, you should have a new gasket(s) on hand anyway in case the old gasket is damaged for whatever reason, even if it is reusable. On the last generation, the rear gasket was reusable. The other option is to use a fluid pump to pull the old fluid out from the fill hole. It works pretty well, although, I prefer to pull the cover so I can wipe out the bottom of the carrier and get all the crud. I don't like reusing gaskets anyway, so I'd be likely to buy a new one. You already know the fill spec. It left the factory/dealer just below the fill plug opening. You can't fill it higher than the fill plug, not without special equipment. Somewhere between the old fill level, and even with the fill plug is where you want the level. The old rule of thumb is to fill until it starts to weep out the hole. Let it settle, check, and then reinstall the plug. It's not that precise. Someone already mentioned the fill capacity above - that will help you purchase enough fluid on hand to do the fluid changes. ..And that's it! No, it doesn't say anywhere in the manual to change the fluid. That doesn't mean it shouldn't be done for good maintenance. What it could mean is GM has a maintenance recommendation of "run to failure" with no preventive or routine maintenance for these. The fluid and component life should last the life of the truck, at least that is the hope. There is a certain satisfaction knowing you've removed any break-in metals, that the fill level is proper, and that both plugs are operational and snugged to the correct torque. Worth every penny.

I spent some time on this today and discovered my "profile" was set up to be primary on only one of the truck's keys, Key 1. I've been using key 2 since I drove it off the lot. The other key I keep in a safe, far away from the truck. I put a check mark next to the other key in my profile also, so the profile should be attached to both keys now. I've been in/out of the truck with the key in my left pocket several times today and it's never honked at me for key issues. Now, when I start it, when it loads my profile it says "key 2 recognized" or something like that. To test the alert, I left the key in the truck, exited, and closed the door. It honked 3x confirming the alert was working correctly and the key had been left in the truck. I'll give it some time to see if it works long-term. So far, it's working...

@AJMBLAZER did you ever figure this out? My 2020 is doing this when I get in the truck with the fob in my pocket, or in my hand. It's driving me nuts.

My 2020 is giving me a triple honk when I enter the vehicle and close the driver's door, before starting it. The fob is either in my hand, or in my pocket--doesn't seem to make a difference, it still honks 3 times in rapid succession. I think there is an option to disable the audible alert for fob proximity via the infotainment controls, but first I want to figure out why this isn't working as it should. With the fob on my person, inside the vehicle, I don't think there should be an alert for this condition. Any ideas?

I don't even care how well it works. I'm not a fan. I'd gladly donate the related electronics for mine, as well. Dangit...missed the cutoff for DFM delete and ASS delete. NOW they decide to make these trucks right....sheesh

Are you turning the switch all the way left to shut off automatic lighting? When the display confirms auto headlights are off, then you should be able to turn on just the park lamps by moving the switch to that setting. If you don't turn off auto first, I think it runs whatever "auto" mode it thinks is correct for conditions regardless of switch input. At least, that's how my last two GM vehicles worked.

OP....nobody is doubting your ability or experience here. Based on the words and pictures, it appears your truck is shifting between 7th and 8th, so folks are encouraging you to explore that more.. That's obviously different from the torque converter slipping, which would be a defect. If locking the trans in 7th maintains RPM's and also keeps the trans out of 8th, that would indicate something is causing it to shift up and down. Maybe a defect or, could be something like dragging trailer brakes or even a light headwind.

Right. But how would one figure what's worse. High levels of metal and other debris in the oil as the engine completes its first few hundred miles of duty, or maintaining a high level of detergent by changing the oil.

Bought the truck new, but it had been sitting 5 months on the lot and was probably moved, idled, and run for short bursts about a billion times. OLM said 95% when I got it; no way of knowing if it was reset, or if the oil was changed at some point. I suppose calling the dealer and asking is an option. Or.. It's got 308 miles on it now and I've got everything to do an oil change if needed. On a previous truck I did 500, 2500, 5000, then every 5k after that. But I'm not sure for the first couple if that's too soon. 5k thereafter seems to be a good balance between being well under the OLM recommendation, and not introducing too much detergent (new oil) too often. I've always used "synthetic" (AcD labeled "full synthetic" or Mobil 1 "full synthetic" - which, as I understand, may or may not be "fully synthetic" but nonetheless seem to perform well for the intended duration, and the ones I use also check the box for using GM-whitelisted oils ala various Dexos spec. Change at 500? or too much too soon? This is for a 2020 5.3 with DFM

I'm not interested in lifting or leveling mine, but I did notice how floaty the rear end is. Feels like the shocks are really, really soft in the rear, and am having a hard time figuring out if it's a defect or why GM would do that. Major motion going over large seams and bumps. So....it's a Rancho thing?

I just replaced mine with a 4" Stubby. Same issue as OP...garage door height barely clears roof, and OE antenna drags. https://www.cravenspeed.com Superior customer service from these folks. The one they sent wouldn't thread on. Either it was wrong, or as they said, there are 2 different thread patterns in use for 20's and 21's. Either way, they sent me the variant model free of charge and made the exchange super easy. Very quick to respond, quick to ship. With *any* shorter antenna, your reception will be affected. Most notably, AM stations in rural areas will be hard to get. If you are in-town and mostly listen to FM, you shouldn't notice much if any loss except maybe for some distant FM stations. XM or other signals are unaffected - different antenna for those.

Old thread, but maybe still worth posting for others looking for a more "official" solution. I won't debate the merits and potential drawbacks of capless fuel filler necks. But there can arguably be a case for preventing crimes of opportunity and/or vandalism by closing off access. AcD makes a locking plug for the capless necks. I'm not sure if you have to use the locking feature to secure it. Personally, I'd prefer to only lock when I felt it is necessary, and not have to carry an extra key on my ring every time I need to fill the truck. Someone else can order one and report back. Part number is GT377 https://www.rockauto.com/en/moreinfo.php?pk=10480808&cc=3445631&jsn=1249

Based on what I know about the 2.4-specific issues and AFM issues is they are separate and a lot more complex than "Dexos sucks", a summary in fewer words based on your ranting about the spec. But explaining the actual complexity of the issue wouldn't support that narrative. You should mention the weak rings put in at the factory. You should mention a poorly designed PCV system and issues with oil being sucked into brake boosters causing the diaphragm to fail. You should also mention the lack of maintenance, ignorance of recommended change intervals, and lack of adherence to even minimum Dexos spec oil in many cases. With regards to AFM, you should talk about oil pressure. You might want to mention deposit formation with regards to direct injection. And high mileage, minimally maintained vehicles with AFM where the filter for the VLOM became clogged, or where it became clogged to no fault of the owner who did actually maintain the vehicle, except for that part. You are absolutely wrong about reasons for ditching ICEs for electric. It's an industry-wide exploration fueled by politics and potential profit, but I can see where that might go, and I'm absolutely not interested in hearing what you have to say. I'm going to maintain my vehicles how I see fit, and you should do yours. Convincing some guy on the internet at this point about oil is no longer worth my time, but I did show up to say you are making false statements and accusations based on an authority you claim to have. Hmm. So this is where I say, "No thank you, I'm not interested in your book of lies and fairytales" and then shut the door.

Ecotec's don't go over 100k? Really? Then why do I know people who run them (who also wouldn't know what an Amsoil is, they change their oil when the light comes on) and they have over 100k on the original engines. Hmm? I'll wait while you come up with something. Are you making stuff up? To defend an oil brand? This just gets weirder, every post.