kpanza

Supposed to go to stealership tomorrow morning to get the order in for my Buyback replacement truck. Any confirmation on whether the 2021 SLT can be ordered with Max Tow AND the Trailer Mirrors AND Tech Package again?

I had a little free time after dinner last night, so I rolled the truck up on my ramps and started looking/feeling around. I grabbed and pulled on everything under there - exhaust, shocks, heat shields, etc. The ONLY thing that was somewhat loose was the spare tire, but only if I pulled downwards on it from the rear...but it didn't move or make noise as I rocked the suspension up and down and sideways. Out of pure curiosity and to rule it totally out, I removed the spare tire completely, and went for a quick drive around the street, hitting all of the areas that cause the noise every day. No change, still there. Oh, and on a side note about the spare tire - if I were you guys, I'd check to make sure yours is tight, and also I'd highly suggest doing something I did while you have it lowered just a bit! My truck is only 5 months old, and I could see two distinct wear areas where the spare tire rubs on the crossmember (when it is all the way UP, the tire butts up against them to get it tight). The sidewall of the tire was getting worn! I suspect over time and a few years, it could make the tire unsafe to use! I grabbed some stiff cardboard I had laying around and wedged it between the sidewall and crossmember to avoid direct contact. With my tire not as tight as it should have been, the movement during driving was causing the wear...not good. Now, I DID hear the fuel sloshing around in the tank as I rocked the suspension, but it's a different noise/feel than the "bowling ball in bed" clunk when backing out of driveway/off curb/turning when going slow noise. My tank was 3/4 full. But I've heard the sound at all fuel levels, so I'm pretty sure it's not that. It's interesting that the noise/clunk happens worst when rocking the suspension side to side more than straight up and down...which leads back to leaf springs. Does anyone know the torque specs on the leaf spring bushing bolts offhand? I'd like to check those after seeing how loose my u-bolts were. On my K5 I generally just tighten til the urethane bushings slightly squeeze for max flex, but I'd use a torque wrench on this truck. My service manager is checking on possible fixes (he's become my ally after my 65 day transmission fix ordeal!) but I don't put much faith in that. Love the truck, but this clunk noise is surely aggravating.

Interesting...I'm guessing our beach weather is nowhere near as hot/humid as WI is this time of year, but I don't remember it staying off very long back in March either when I first got the truck. a/c is set to 72, our average daytime temps lately are high 70s, low 80s... Well, I didn't buy the 6.2 for mpg, but it would be nice if it could at least beat the 10 year old truck with its lower gears and 4 fewer trans gears!

Hey guys, just wondering if you could chime in on how LONG your truck will stay in the "Auto Stop" condition (for those of you who don't disable it every time you get in truck). I just read some GM marketing blurb on the system, and they are claiming it can stay in the Off condition for up to two minutes?? The longest I have ever gotten mine to stay off is like 35 seconds, and often is less? I am used to the technology, as our 2018 Pacifica has it, and it can stay off for 1-2 minutes easy if the conditions are right? Wondering if I need to have dealer look at the auxiliary battery if mine isn't working right? My driving is 80% city, stop and go, so it would obviously have more of an effect on my MPG if it was shutting down for longer at lights? Truck is a '20 SLT 6.2 with max tow, am averaging 12.9mpg over first 1850 miles...so far is worse than my '10 Silverado with 6.2 and max tow (and it had 3.73s!) was.

I agree, it is just bigger in every way than my 2010. With a 4 year old and the wife in the car most days, I am not hot rodding it...I'm actually TRYING to eke out a bit more MPG most days, but it doesn't seem to matter...so far is just stuck in the 12-13 range. And this is on 91 (highest we can get in So Cal), not 87 octane...it does have the optional All Terrain tires on it, not All Seasons, but that is not gonna explain difference either. One thing I am wondering about is the Stop/Start system - I don't expect it to make a HUGE difference, but how long does yours shut off for at a light/stop, etc? Because mine only shuts off for about 15-30 seconds max? It doesn't stay off ANYWHERE near as long as our Pacifica minivan does? That van will stay off for 1-2 minutes depending on how hot it is, a/c on, etc? But my truck, in exact same conditions, driving style, etc, it will start back up super quickly...like I said, I've timed it and it's off for no more than 35 seconds at the longest?

Averaging 12.9mpg over first 1850 miles. SLT Crewcab w Max Tow. Mostly city, but a couple longer highway trips thrown in. Averaged about 18 on last trip 200 mile trip to mountains and back. But in town, it struggles to get more than 12-13mpg (like others, includes lots of idling with a/c on, eating lunch inside some days, etc). Best scenario I ever got was about 24mpg with cruise control set at 67mph, all highway (flat more or less) for about a 30 mile highway jaunt... Can't believe that the 3.42 gears knock it down dramatically, but I sure as heck am not seeing this 18-20mpg a bunch of other guys claim! I sure wish I did though! My 2010 Silverado 6.2 (max tow with 3.73 and 6 speed) averaged 13.9 over it's 36,000 mile lease with me, so I was hoping this one would do a bit better in same driving conditions.

Yeah, this is a widespread issue. I suspected it was due to my woefully under-torqued leaf spring u-bolts (lucky if they were at 40ft-lbs of torque!), but even after tightening them to the recommended 85ft lbs, didn't change the clunking noise. Mine has been doing since Day 1, but my truck spent 65 days in service for a transmission problem, so I am leery about letting it sit there at dealership any longer. I've checked shocks, u-bolts, spare tire, etc, nothing obvious at this point. But every time leaves load and unload (backing out of driveway, pulling in, over speedbumps, etc, get the bowling ball in bed noise). So embarassing when passengers ask what is that noise? I just turn up the radio... Guys have gotten the leaf springs replaced, new isolators in between leaves, etc, still not sure it solved it. Just so we can compare trims, etc, please state your exact truck specs: Mine is a '20 SLT 6.2L 4x4 Crew, with Standard bed and NHT

If you want to know for sure, get underneath and look at the casting numbers...otherwise, you can email GM and get the build sheet with all of the specific RPO codes for your truck. But easiest is to just get underneath and look...see the other pictures in this post. Directly behind the pinion, on a casting rib in the axle housing...

I just saw that other thread about the 9.76s...leave it to GM to print ONE thing and DO another! haha It makes sense, as the high torque of the 3.0 and 6.2 are definitely suited to the 9.76, but I was just going off what GM itself had in print. Reminds me of the old days when OEMs would have surpluses of this axle or that axle and just stick in what they had laying around!

Just to clarify one thing, the Max Tow pkg (NHT) DOES come with a different rear axle housing (as well as lower 3.42 gear ratio) than the non-NHT trucks.

Any of our Canadian friends have experience with these Goodyear Wrangler Territory tires? Looks like that is the new optional All Terrain tire ($200 option previously). I REALLY like the current Bridgestone Dueler ATs that came with my truck, they perform really well and ride really nice and quiet, plus they don't look half bad? Hope these new Goodyears perform as well, have had mixed results with Goodyears in past...

It looks like the fine print on that order guide also requires the trailering mirrors to get the Tech Pkg on the SLT - which is great! Never understood why GMC didn't let you order the trailering mirrors on the SLT, when you can order the Max Tow?? Also, I have the 6.2L and Max Tow (which I love, other than the 65 days in shop to fix the transmission, and reason GM is buying it back), but has anyone heard if the GM engineers came through on getting the underhood engineering done to allow the 3.0L Duramax to have higher tow ratings (maybe even Max Tow ratings?)?? I'd be mighty tempted to go the 3.0L route if they did that... But I am excited to hear about the Tech pkg on SLT, I really hope that is available for real finally...with the added benefit of the trailering mirrors!

That would be awesome if the Tech pkg is available on SLT in 2021! In process of having my 2020 SLT exchanged by GM, been waiting to see what changes were coming on the 2021s before I ordered! Also, you guys going back and forth about double cabs/crew cabs and bed lengths, you DO know that you can get a crew cab with the 6.5" bed, right? I have one...as do lots of other guys. Is the best of both worlds - awesome interior space, usable bed. They aren't as common, but they are available if you look...otherwise just order one!

As stated above, no, your AT4 cannot have the NHT Max Trailering pkg. But since GM is so wise, your AT4 COULD be optioned with the Trailering mirrors, plus the Tech package that has all of the cool trailer camera provisions...but, my SLT, which does have NHT Max Trailering CANNOT be ordered with the trailering mirrors or the tech pkg with the trailering camera stuff...weird, huh? My old '10 LTZ Silverado, the NHT got you the 6.2L, the upgraded axle, cooling and the mirrors...I guess GMC thinks Denali and AT4 guys want the mirrors and SLT with NHT doesn't? Oh well...

Well, I have truck back. They replaced the front case cover, front seal and torque converter. They drove it about 25 miles and so far no leaks. Fingers crossed that this 66 day saga is over and I can just enjoy the truck. Hopefully this is not a widespread problem for others. They did at least follow my request, and they did a full detail on the truck, plus filled it with gas. They really want their completely satisfied review!

So, after 65 days out of service, the dealer called and says the transmission is fixed. Going to pick it up tomorrow and find out. I am going to drive it a few weeks and see if all is good, then decide what to have GM do. I'll either get it replaced (was approved for buyback/replacement last month), or get GM to compensate me for my 4 payments already made. Not much inventory to pick from on the replacement end, so we will see. I really just want to drive the damn thing and enjoy it. Fingers crossed. I'll let you know what the actual service receipt says was replaced, as the service writer has no clue. All I know is it is NOT a brand new transmission, as there aren't any available at the moment.

Weird! Replaced a few of those in the 208 and 241 t cases in my K5s! Easy fix, glad they took care of you.

Wow, that's much further back than mine...at least that's an easier fix. Good luck.

Consider yourself lucky! At 270 miles, mine went in for leak, and they replaced the torque converter seal...few days later, it was brought back because it was still leaking! And now, my truck has been at the dealership for 63 DAYS AND COUNTING! They say they are waiting for a transmission pump. Service manager has requested a new transmission, but nothing from GM. GM has approved a buyback or replacement due to CA Lemon Law, but finding a similar truck (and getting a far away dealer to actually dealer-trade it to my dealer) has been impossible.

Not the cooler lines, at least not on mine. Starting to think this 10spd has issues...go on the Ford forums and there's all kinds of complaints like this. Mine wasn't even the pan leaking, is something internal. If they ever actually fix it, I'll let you know what they come up with this time.

Mine was 2/04/20 build, Mexico. 6.2L/10 spd. Still at dealer awaiting a pump, or a whole tranny, or whatever the hell they come up with next. I picked a replacement truck from their inventory last weekend, was told that the truck was "off the floor", was mine for the GM Replacement...later that day I get a call that the sales manager sold it from under me. Might just get my money back and tell them all to pound it.

They said they did the dye in my transmission, and found "no further leaks"...yet, couple days later when I got it home, trans fluid all over driveway again. And just FYI, my truck has now been at the dealer for 60 DAYS now! GM has approved a buyback, but there are literally no trucks comparable to mine available. Trying to see if GM will ship something from a dealer 1000 miles away, but so far no answer. My dealer rep has argued for a complete NEW 10 speed from GM, but so far nothing. So ridiculous. On my 4th payment, and driven the truck all of 300 miles over a couple weeks.

Interesting...my 275 mile 10 speed leaked from day 1 also...they replaced the torque converter seal, still leaked (was in shop 2 weeks that time). Is now on Day 58 IN THE SHOP, they are waiting on a new trans pump...but my dealer rep has requested a new transmission, so far no answers. Really disappointing. Have now made 4 payments, and got to drive the truck a grand total of 3 weeks between repairs. GM has approved a buyback or replacement, but now there are hardly any trucks to choose from.

They had it for two weeks, replaced the torque converter seal. Leaked even worse. Has been back at dealer for last two weeks, they are claiming pump and seal need replacing now! But no idea on parts availability, so it's just sitting there. Thursday will mark 30 days out of service, at which point I will likely go Lemon Law. Ridiculous. My buddy has an SLE, his was in shop 6 weeks total, had trans and engine oil leaks...starting to wonder?? His was the 2.7L four, they had no engine pans available because of strike when his was in late last year.

Truck goes back to dealer for transmission leak (2nd time now) tomorrow, and now another issue has popped up. Anyone else experience their windows making a rubbing/jerking noise when powering them down? Only happens on my driver's front window, and only when powering it DOWN? Doesn't happen on way back up? And none of the other three windows do it? Hoping there is just something dirty in the track or weatherstripping. You can see the window "skipping" on the way down as it makes the rubbing noise.