todd308

The only thing that worries me with the rotopax is I would want to make sure the fuel module rested it's weight on the bed, not by their hangers, not sure how well these aluminum beds walls will take 20-35lbs bouncing around flexing the bed sides. Probably not a big deal if you're not off roading but there was recently an article where a bed mounted spare tire on a ford cracked the bed walls on both sides (two mounted tires). Unfortunately due to NHTSA it's basically impossible for companies to manufacturer gasoline replacement tanks here (diesel only) that automatically feed into the factory tank. Similar reasons are probably why some containers that might work perfectly fine for fuel will have disclaimers saying not to use them for fuel. You can do a gasoline transfer tank in the bed that isn't connected to the factory fuel system, Titan I think makes a couple that also double as a truck tool box. There's also the Titan 15 gal sidekick option that sits from one wheelwell going forward, but depending on the truck it may not fit under a tonneau cover. https://titanfueltanks.com/titan-sidekick-15-gal-portable-liquid-tank-5040015

Lots of guys say they want this, but few will pay for it, and those that really would pay for, have probably already had Hennessey do it. You can probably add at least $15k to the truck price knowing GM, and if you really want it. You can order a Hennessey upgrade to a supercharger from the dealer on a new truck, or have them mod your current truck. Not only that, but in a factory truck, now you have the same problem as Raptor's and TRX's, huge market adjustments. The Escalade is a great example......the current most expensive Escalade you can build right now is about $125k.....and that's adding in every ridiculous add on you can check..refrigerator....performance everything, sunshade, brakes, exhaust, $3k wheels....yet the new supercharged one STARTS at $150k. For that $ you can buy a new CT5-V blackwing and an AT4. Even in the CT5, moving to the the supercharged 6.2 in a blackwing is a $25k option.

Yeah that sounds really odd that you have one fan doing one thing and the other fan doing the opposite. I wonder if they got some batches of badly wired fans/harnesses. On mine yeah both the seat surface and seat back pull air in, on both seats and exhaust under the seat. Which isn't too surprising because the fan module/part number appears the same for both sides. No idea if the upper fan in the seat back is the same type of fan or something different.

Yeah it just seems interesting that some push and others pull (even across 21' GMC AT4's) Not sure why they did both, parts issues etc. What I can say is that the push version works 10x better than the pull version. I'd be tempted to wire mine in reverse to see if they would push, but the upper fan in the seat back is also pulling so I'd imagine getting to that one is not going to be so nice.

Yeah I dug into this further today and I think they must have changed the design from 20' to 21' at least in my AT4. My 20' definitely took in air under the seat and pushed it through the seat. You could lay a piece of paper on the seat and it would "float/flutter" with them on high. I just tried this in my 21' and it sucked the paper to the seat, passenger seat is the same way. So they either changed the design or mine is wired backwards and the fan is running the wrong way. What I can say is my 20' the blew air through the top of the seat was MUCH more effective than my 21' that sucks it through the seat and exhausts it out the bottom. There's definitely something amiss, I posted the same question on a couple of the AT4 facebook groups and others have already chimed in that theirs definitely blow air up through the seat, 21' models verified. So either something wasn't wired right, the fans were a "covid" manufacturing QC victim, or GM changed the design during the year (perhaps due to part shortages). Could be a manufacturing issue, they use the same part in both seats so maybe a batch of them were wired wrong.

Yeah that's my thought, if I take it to the dealer they are just going to say "well the fans are spinning it's fine!" Not to mention that we've seen a lot of horror stories about dealer techs not putting the seat covers back on right/tight and they end up being way too loose. It will be the same as when I took it in because the HUD bounces more and is slightly blurry compared to my 20' model, guy took a look at it and said "well I can read it, it's fine".

Auto for those items (steering wheel, seats (heat/vent) is interesting, not sure if I'd like it or it would be too much, but you can always turn it off. I know the pickups will do the heated/ventilated seats if you autostart it as long as the truck is at a certain temp and it's engaged from the infotainment menu settings. However like most of the indicators when the truck is autostarted they don't illuminate on the dash. I can say I do wish the steering wheel had more than one heat setting like the seats do. It's just very odd because clearly by the arrow on the fan it airflow is going the right way, and the fan is running (at least the lower fan, no idea about the upper one in the seat back) but there's basically zero airflow, at least barely enough to notice even with the cabin cooled down with AC. In my 20' after a couple minutes you'd be turning it to a lower fan setting because it was too cold. I've also been really careful what I clean/condition my seats with and how much after reading horror stories about guys plugging up all the holes with seat cleaner/conditioner. I've tried a stiff brush on them, and also vacuuming them to make sure the holes were clear.

Does anyone understand how the ventilated seats work? Where in the intake/exhaust is, ducting etc? I'm trying to figure out why mine don't work worth a darn in my 21' but worked okay in my 20'. I can clearly hear the fan running when I start it on both seats, but they really don't move any air through the seat even on high. Even on high with the AC on foot so it's blowing cold air under the seat itself you can barely feel them in the seat bottom, and not at all in the back. In my 20' even just turning them on full blast without the AC under the seat would be freezing your nuts after a couple minutes. What I noticed is on the underside of the seat, for drivers seat, on the left rear under the seat there's a round squishy pad, I assume this is the intake for the fan. However to the side of that there is a lot of air blowing out toward the middle of the seat and it looks like perhaps it should have something attached to it. Especially since it seems like it should be blowing air into the seat, not under it. I tried to get a picture but it's almost impossible since there's not enough room under the seat to focus, but it feels/looks like something perhaps connects to it that's not there. Tried looking up the part info, but the drawings don't really have much detail, tried searching for images but I don't see anything that looks like what's under my seats. I did find an acadia 2021 ventilated seat blower, and it kind of looks like this. Minus what I assume is a filter that goes over the bottom. There's a port on one end that has an arrow for airflow (circled in red), but is that supposed to connect to something? On my truck it appears to just be unconnected and blowing air freely under the seat. Passenger side is the same way.

I don't disagree it's certainly the CAFE standards that drive striving for fuel efficiency for manufacturers. That said Ford (36gal) , Ram (33gal) , Toyota (32.5 gal) all figured out a way to get more than 24 gallons in their vehicles, even if it's only as an option. Last I checked they all have to deal with the same standards. For GM this simply reeks of cutting corners to save cost.

Seats are quite poor in these GM's compare to the competition but seats are an individual thing. GM's are quite hard, some like it, some hate it. They also have very narrow seat centers with small bolsters so you tend to slide around on them more. As for trading if you're going to do it, do it now, used/trade prices have been tanking, not sure why if it's the 22's coming out, gas prices, economy, they've burned through all the suckers willing to pay huge markups, etc. but I've seen offers from places like Carvana, GiveMeTheVin drop $6-7k in the last 2 months. Gas mileage, honesty I never believe half of the reported numbers you see on forums/facebook, you'll see guys claiming they get anywhere from 25mpg to 10mpg with the same engine/truck/driving (city/hwy). Read the EPA testing course for city/hwy numbers, it's super granny driving. You are unlikely to ever beat those numbers over thousands of miles, any claims of beating those numbers by 25-30% I'd take with a bowl full of salt.

Haven't owned either, but between the two I think I favor the Bushwacker version, not only cheaper but seems like better coverage. https://www.bushwacker.com/Truck-Trail-Armor-Rocker-Panel/2020/gmc/sierra-1500 It's not only mud/rocks, but with the high clearance steps being so narrow and tight to the truck, your shoes/boots etc. can frequently beat into the rockers, even if you're careful. Get mud/salt on those rockers and then grind it in with the toe of a shoe just once and it will scuff them up. We see a ton of them that have paint damage there very quickly. PPF is another option to do for that issue.

Yeah, basically that's what I'm seeing in my post above that led me to believe it's doing more than just L-9 is. For my 21' in L-9 it also will never get to 99 coasting downhill, it sits in the mid-upper 60's, low 70's usually, don't think I've ever seen it in the 80's, Pulsar I don't think I've ever seen get above the upper 40's. Father put a Range in his, admittedly much older 2007 6.0L and he also noticed that it cut the instant mileage while coasting, so it's interesting that it doesn't seem to impact it at all on the AT4's. A lot of folks have reported odd phantom issues with the Pulsar. I haven't had any, but I will say that when I tried out the throttle sensitivity settings I found that the truck didn't idle nearly as smooth in settings other than "stock" and I actually felt like it had more hesitation. It definitely made the throttle more "touchy" but it would hesitate a bit more when you first stepped on the gas, set it back to stock and it would instantly improve. I had also hoped that you could do the DFM delete but keep autostop enabled, just because i get stuck in a lot of stop/go traffic so it makes a significant fuel difference for me. However it seems to be the truck won't autostop if it is in v8 mode. Even with the Pulsar set to allow autostop and it illuminated on the truck console, it will never actually shut the truck off. It won't in L-9 either so my guess is once you mess with the DFM, it will never shut off.

I've wondered if this is really true and this is why. When I run my AT4 in L-9 (or M-9) you are right it drops the instant fuel economy down from just being in Drive, coasting down the same hill everyday driving to work is an easy way to check. However, I've wondered if it's doing something in the middle (for example letting DFM shut down up to 4 cyl but not all 7. The reason I say this is because when I run the Pulsar, the instantaneous mileage is even lower than it is in L-9. This leads me to believe that L-9 might be doing something "in between" what having all 8 engaged all the time does and full DFM. Unfortunately it won't save the lifters, the problem there is the lifter integrity itself, not a result of DFM. It's amazing what these engineers (probably forced by company bean counters) will sacrifice to get a bit of MPG on the window sticker. It's why we have front bumpers that barely clear a curb, why we have DFM and self destructing lifters, front end rake so the truck looks like a door wedge from the side, and tiny fuel tanks. There's a video talking with the head Tunda designer for the new Hybrid tundra. They used to have a 38gal tank, and their goal was to be able to drive 4 hours towing at max capacity. When they got the hybrid they gained MPG so they shank the gas tank 6 gallons and he even states they did it to save weight to gain MPG. That's right a whole team of truck engineers thought it was a better idea to save 50 lbs of fuel on a 5500lb truck to gain some tiny fraction of MPG rating, than give the driver 20% more driving range.

My 20' had the GM soft tonneau cover, and I put the LoPro on my 21'. I have to say for basically the same price I prefer the GM model. I had to do a lot more sealing to get my LoPro not to leak, even with the seals it leaked like a sieve at the front corners. Not only that but the GM cover had an extra support bar, so water pooled a lot less on it. Even tugging my LoPro super tight there's a huge lake when it rains. I also liked the tension control on the GM model better as it was adjustable at the tailgate, instead of at the front corners and it sealed much better except at the tailgate itself where the LoPro "flap" works pretty well. As an aside if anyone is considering doing the Truxedo Elevate TS t-slot rails with their Truxedo cover I don't recommend it. First they shorten the distance between the cover rails by about 1/2" so the cover velcro does not fit as nice because the rails end up being shorter distance between, and they also are really flexy when pulled in the direction of the center of the truck or upward (as they would be if you used them for tying things down etc., I would never trust them to actually hold anything mounted to them or tying any heavy cargo to. Basically they are just a thin L bracket that only has about 1" of overlap with the bed rails/clamps between the bed cover rails and bed. I was going to use them for a bike rack setup but they were just far too flexy (even with 6 clamps a side) to trust.

The mindset for these car companies is less fuel = less weight = higher MPG # on the window sticker, it's really all they care about these days. Now that sounds insane, but there's a video out there from the head guy talking about the 2022 Tundra, that used to have the largest fuel tank 38gal. He was saying their goal was they wanted someone to be able to drive 4 hours towing max weight. Because they went to the new hybrid, it got better mileage, so they shrank the gas tank 6 gallons so you could still drive 4 hours, and the reason they did it was to save fuel weight and increase gas mileage. Think about that a bit, a "truck" designer, heck a whole team of them, felt it was better to get rid of ~50lbs of fuel weight on a 5500lb truck, for the MPG increase, than give the driver 20% more driving range. The level to which these car companies will go to gain tiny MPG amounts even on trucks, is insane. It's why we have a 24gal fuel tank in a truck that gets 8mpg towing. It's why engines are eating lifters with DFM, it's why the front valance can barely clear a curb, and it's why the autostop comes on every time you start the truck and who knows how many other things.

Bit of a necrothead but an update. My 21' also started streaking under the attachment point as we come out of winter, not quite as bad but significant. I don't think snow bent the arm because we had almost none this year, my truck is usually in the garage. Trying new OEM wiper blade to see if that fixes it, as a precaution since it was like $20 and it has helped others I also ordered a new wiper arm. I haven't installed it yet, but the spring attachment looks interesting to me, it appears they just use a "C" style hook to connect the spring to the arm near the vehicle attachment. The spring seems super tight but not very stretched at rest. I wonder if what is happening is over time that "C" attachment is bending/lengthening a bit and weakening the effective spring tension. I don't think it would take much to change the wiper pressure significantly. If the new wiper blade alone doesn't fix the issue, it will be interesting to compare this new arm to the original to see if it's obviously stretched out. That or to play with the old "C" and add some tension back in and see if it fixes the issue. Picture of the attachment and bent "C"

For those that have dropped to a 1" rear spacer from the 2" how much did it level the truck? I don't tow heavy, and it's unlikely I'll be putting 1500lbs in the back of it anytime soon, and with all the problems doing a level up front with UCA's, ball joint failures, CV joint issues it seems like that's just a bad option. I don't mind some rake but these AT4's look like a door wedge even compared to the normal Sierra/Silverado, my guess is because GM didn't want to lift the front end properly to save $. I know the TB/AT4's have what looks like ~2" spacer under the rear leaf spring pack. Has anyone that's done a 1" spacer (my understanding is that's what comes on the non-lifted Sierra's) to level it out a bit happen to have the part # they used? Looking at all the GM part sites, many of them don't even show an entry for that part #9 in the rear suspension section, and those that do list 2 options but the part information isn't useful to deciding which is the correct option. For example if you look up 2019 GMC Sierra 1500 Elevation, they list two options, however both options say they fit 2019 all Sierra/Silverado trucks, the only thing they mention is with or without code 4507 but there's no info on what that is. https://www.gmpartsstore.com/v-2019-gmc-sierra-1500--elevation--5-3l-v8-gas/rear-suspension--rear-suspension If you try looking up 2020, or 2021 rear suspensions for Sierra's (non-AT4) they don't even have an entry for the rear leaf spring spacer in their list, just the diagram. Tried the search but didn't find much info from people that have actually gone to a shorter spacer, or any part #'s. Thanks

When I got my 21' AT4 the dealer installed the Keyless Entry Keypad, and gave me the card with the Master Code. To be honest months went by and I never really messed with it aside to verify the master code worked, but the other day I thought I'd actually set a code on it. I used the Master Code on the card and it unlocked the door as expected. Then I tried to set a new personal code (holding 1/2 after putting in the master code, then my personal code), and it has not worked since. Not sure if I didn't hit the code I thought when I was reprogramming it etc. The odd part is from what I can tell from the FAQ on the GMC page for the accessory, the Master code should always work, even if you set a personal code. Mine no longer responds to the master code. Q: What do I do if I can’t remember my five-digit code? A: The included wallet card contains a five-digit master code that will unlock the vehicle in the event you should ever forget your personal five-digit code. (They really should give you the info on the FAQ page, the instructions on the back of the master code card are worthless) I talked to the dealer and they said the master code should work all the time and they had no ideas. Anyway it seems to be a brick right now, but it still does talk to the truck, as I can still lock the doors with it. The FAQ talks about the unit locking itself out for increasing amounts of time (more wrong entries the longer the lockout) but that seems to only be if you put in 16+ wrong entries in short time periods to stop scanning attacks, and the orange light is not flashing on mine indicating it's locked out. I didn't mess with it over the weekend and the master code still won't work. Seems like a silly thing to take it back to the dealer for, so I thought someone might have some ideas. Thanks

Bit of a Necrothread but does the Master code stop working after you program a personal code? I just tried to set mine up, master code worked fine, so I tried setting a personal code. I don't know if I didn't hit the buttons I thought I did (personally I think the split buttons 1/2, 3/4, etc. are easy to make a mistake on) but the code I thought I set does not work, and now neither does the master code. Is this thing now just a brick?

Bit of a Necrothread but does the Master code stop working after you program a personal code? I just tried to set mine up, master code worked fine, so I tried setting a personal code. I don't know if I didn't hit the buttons I thought I did (personally I think the split buttons 1/2, 3/4, etc. are easy to make a mistake on) but the code I thought I set does not work, and now neither does the master code. Is this thing now just a brick?

While my example of course is a bit tongue and cheek it exposes the ridiculous nature of the defense. Off road lights are not really a good example either, because as long as they are turned off there's no violation. Perfectly legal with to mount/modify the vehicle with and drive on the road. It's only when the driver decides to turn them on driving on the road that there's a violation. Tinted windows are not the same, they are illegal on the road at all times, there's no "functionality" to them that makes them legal/illegal on the road. Perhaps that could be the tint shops new defense! "Well the driver promised me they'd always drive with the windows down and only put the windows up when the car was parked!, I guess they forgot when they left!" Non-road legal Show cars and Off-road vehicles would be easy to spot, they'd arrive on a trailer to the tint shop or the tint shop would have to come to the vehicle off site. If the vehicle is driven to the shop, it's fair to assume it's road legal, at least the shop should not be responsible for making sure it is. Now if someone trailers their car to the tint shop and tells them it's a show car only and not for road use, that of course would be different. Now the customer is purposely misleading the shop by lying about the vehicle's ability to be used on road.

Yep, this has become quite common in PA now, probably because so many have illegally tinted front side windows and people love to run stop signs so we see a lot of accidents where someone turned into someone else. You go from "well it's an accident and it was your fault but these things happen" to "You illegally modified your vehicle to impede your visibility and caused an injury accident." an injury attorney can do far more with the later. Insurance companies will also go after no-fault accidents (say in a parking lot) if one party had tinted windows and it was at night etc. where vision could have been a factor. What I've always wondered is why states/DOT don't go after the tint shops knowingly illegally modifying vehicles. If the states feel it's a safety issue, then it would seem like any shop that tints them would be modifying a vehicle so it's unsafe. I've read where tint shops will defend themselves saying that it's only illegal if you drive the car on the road and since they tint it in a shop it's legal until the customer takes it back on the roadway, and that's the customer's decision so we're not at fault or there will be an "For off road use only" disclaimer on the receipt. It would be like a gun shop selling guns to felons defending their actions saying "Well I processed a sale for him, but I just put the gun out in the parking lot, I never gave it to him and I never saw him take possession of it. He decided to pick it up in the parking lot, but I didn't give it to him, so it's okay!" The same is true for the excuse some shops use where they will tint anyone's windows illegally because some people might have a medical exemption for tinted windows. Which is true, but in most cases where you do something others typically cannot due to a medical exemption it's usually required you provide proof of the exemption. For example in some states if you have a disability you can hunt the archery season with a crossbow, but no state is going to put that exemption on your hunting license without you proving you have the medical disability that makes it so you cannot pull a normal bow.

It all depends on if they adjust the angles, it's the extreme angles that usually make those parts fail. I'd be very surprised to see the upper ball joint angles be the same or worse (since it's 1" taller yet) than the TB/AT4 is now. CV angles are the same, if they drop the diff a bit, or I'm sure adjust any number of other items that impact suspension geometry and correct the CV angles they also will be more durable.

There's a reason why you can put a 2" level on a stock silverado/GMC (non AT4-TB) and never have an issue with ball joints, cv joints, UCA's but if you do the same thing to a AT4/TB we see guys with front wheels coming off, upper ball joints failing, CV joint issues. The upper ball joint angles are already bad on a AT4/TB stock. If the suspension and drivetrain angles were adjusted for the extra lift on the TB/AT4 we wouldn't see this happening only on those models. You also wouldn't see lift/level companies giving special restrictions only when levels are used on the TB/AT4 like don't use 4-auto etc. There's a reason dealers that are happy to install level kits on non AT4/TB pickups refuse to do so on AT4/TB's. If the suspension angles were the same, it wouldn't matter what model it was. It's why when you go to Ready Lift's webpage and look up options for a 2021 silverado they offer 2" level kits without UCA's and with zero restrictions, but if you look for options with a TB/AT4 your only option is a 1.75" level that includes new UCA's, or a 2" kit that also includes UCA's and the restrictions say not to use 4-auto. "When combining a traditional leveling kit on these factory lifted trucks, several issues present themselves including binding problems with the factory control arm ball joint and contact concerns with the lower strut/CV axle assembly." Strait from RL's webpage. Head to Rough Country's webpage and you'll find the only level they offer for the TB/AT4 is a 1.5", their 2" kit specifically says not to use it on TB/AT4 Now personally I think GM has a UCA/upper ball joint weakness issue, and 5-10 years from now we'll probably see these have issues even on stock AT4/TB trucks (we've already seen a couple failures on stock AT4's posted), but putting a level on increases the likelihood of failure, even more so with the AT4/TB. If I was putting a level in any of these trucks, considering once you do GM is not going to cover a UCA/ball joint/CV failure or any other driveline/suspension damage that happens, I'd be replacing the UCA's, partly because I don't want to have a suspension failure and be stranded somewhere or have it cause an accident (hard to steer with only 1 front wheel on) and partly because if there is a failure GM isn't going to cover it. We've already seen posts on the FB AT4/TB groups that dealers have gotten notices from GM to not cover any front end suspension/drivetrain issues if a level is installed.

It's not a spacer but it's nothing more than a longer strut assembly but with the same shock travel. So while it might not be a spacer, it has the exact same effect, there's no more wheel travel and no benefit to the suspension at all, they just made the fixed shafts longer. In the rear all they did was shove a spacer block in. Showing again just how far behind GM is falling. While the other big manufacturers have gone to real suspension travel increases, with linkage rear end suspension, allowing for less squat towing, better bump compliance, and way more wheel articulation. GM is starting to catching up with the ZR2/AT4-X to where the raptor suspension was 10 years ago, except they still have way less wheel travel.