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"up to a +13 hp improvement at 5600 rpm and up to 8 additional pound feet of torque at 4100 rpm" Key words "up to", and notice the RPM's where those potential max gains occur. What do the gains look like at between 1500 and 3500 where these engines spend most of their time? CAI's and CAT back exhaust systems just aren't going to make a noticeable difference at lower engine speeds. The stock AI and dual exhaust systems are more than capable of flowing enough CFM probably up to 4-4.5K RPM, and the stock air intake is already pulling air from in front of the radiator, not from the engine compartment. If those aftermarket bits do add anything at lower RPM I'm hard pressed to believe one could actually feel it. You could have a 3 or 4 HP/TQ variation from day to day just due to atmospheric/barometric pressure changes.

While you're not wrong to be concerned, some of these potential issues are way over blown. 1) If the battery drains to the point the truck can't be jump started at the dealer, or fails to hold a charge afterwards, it should be replaced under warranty given the age of your truck. 2) Flat spotting mostly happens when a tire(s) is significantly under inflated. Unless one of yours has a leak it is unlikely they will lose enough air to make permanent flat spotting an issue. I have an old car in my garage that doesn't get driven for months at a time. I can tell the tires feel like they have slight flat spots but a few miles of driving takes care of it. 3) That takes a long time to happen. It's mostly an issue with condensation (moisture) accumulation in the oil and trans fluid from short run cycles where the fluids don't reach operating temp. If it's not being started at the dealer there are no short run cycles. It's possible there was already moisture present when it got dropped at the dealer. The additives just don't degrade much from sitting. Engine coolant won't be affected, nor will brake fluid. The trans fluid will be drained when they do the valve body. If you are concerned about the oil have them change it. 4) No more of an issue than if it is sitting in your driveway or garage. Driving it doesn't counteract the exposure to moisture. The brake rotors might develop a coating of rust which a quick drive will scrub off. Moisture might cause the rear brake (sliding) calipers to hang but unlikely. 5) Not likely an issue while it's sitting in the dealer's lot. Not exactly a wooded area where those kinds of critters live. 6) Sure, but damage due to constant exposure is likely to take years. 7) True, but again it takes quite a bit of time for the fuel to degrade. Again, my old car sits for months at a time with ethanol gas and it never has an issue. My boat would also sit for months at a time, also without issue. I'd be far more concerned about body damage while it's there.

That's usually the case when a recall happens after someone has paid to have the repair done. Save the repair paperwork.

Doesn't appear that anyone outside of GM knows what the failure point in the valve body is, and there might be multiple failure points. Many people in this thread reported losing reverse but mine didn't. Interesting that GM couldn't find a VB for yours, but could find an entire transmission. How long was your truck out of service?

The 35's also reduce towing capacity because the larger diameter effectively reduces axle gear ratio. The additional weight of the 35's also reduces braking capacity due to the increased flywheel effect; longer stopping distances. Given the non-factory lift, the non-factory tire size, it's almost a certainty that GM won't honor the warranty should something in the power train fail for any reason. A warranty denial could be expensive. As well, the truck may be insured based on the factory specifications (discoverable from the VIN) which have now been changed, so you might consider contacting your insurance company to ensure they'll cover the truck with the modifications, in both towing and non-towing scenarios. An insurance denial could be catastrophic.

Your symptoms sound exactly the same as mind did; no warning, pulled out of a gas station, drove maybe a couple hundred feet, then got a bunch of DIC warnings, wouldn't up shift past maybe 4th. Still had reverse though, I think. While mine now seems fine complete trust is still 1000's of miles away.

From what I've read a weight distributing hitch does not decrease tongue weight. Is that 955 trailer tongue weight with the trailer fully loaded? The owners manual says that trailer tongue weight must be added to GVWR of the truck. The truck's sticker says your curb weight is 5633; that's ready to drive but otherwise fully empty. 5633 + 880 = 6513. The truck's GVWR is 7200, which leaves you with a margin of 687 pounds for bodies and gear to put into the truck and the bed. Even without the tongue weight issue, if you max out the GVWR of the truck to 7200, and max the trailer at 9710 you'd be at 16,910, 2000 pounds over the max GCWR of 15,000. You'd need to shed 2K pounds just to get to the max GCWR.

Glad you got yours back so quickly. The "trigger" for my repair seemed to be when I opened a case with the BBB. I got a call from a different customer service organization within GM the very next day after I opened the BBB case. Evidently those BBB cases get routed differently and, it appears, GM jumps on them. Mine got fixed about a week later.

I haven't read of anyone here that knows what is failing in the VB, but I have to guess GM engineering has done the forensics and knows what fails. If they do know they aren't making it public knowledge, natch. We do know the original VB P/N has been superseded by at least one new P/N. The 10 speed VB has a bunch of solenoids, and associated rods/plungers and springs. Probably a check ball or two. If any of them don't or can't go where the TCM tells them to, for whatever reason, failure.

They are really nice trucks. The interior is what sold me on my 2023 Silverado HC. The dash layout is almost identical between Silverado's and Sierra's, and there are some aspects of each I like over the other. Same with the exterior. I didn't like, at all, the factory wheels that came on the '23 HC's so those got swapped out with some GM wheels that were a factory option. That black truck in your 3rd picture has them. Also not a fan of the factory "HDMI" exhaust outlets so those are getting swapped out with a set of really nice polished SS "quad" (two pipe outlets for each side) tips that bolt in just like the factory outlets. You can download the manual and save it on your computer. Manuals and Guides | Vehicle Support | GMC

FWIW, mine has been fine since the VB replacement, though I've put less than 500 miles on it. Perhaps GM is catching up on all the VB back orders. I've read recently that NHTSA is investigating engine failures with the 6.2, which could result in a recall, either forced or voluntary, and my bet is they are investigating due to the number of people who've filed a complaint with them about 6.2 failures. So although this thread is focused on the 10 speed transmission VB, if enough owners take the time to open a complaint with NHTSA for the transmission problems the NHTSA will be obliged to open an investigation for that issue too. As I suggested in a previous post open a case with GM Customer Care, with BBB Auto Line, and with NHTSA.

I doubt the noise is VB related. At idle the VB isn't doing anything, none of the solenoids are active/cycling. I recently watched a video that, in part, talked about the wildly complex torque converter GM uses with the 10 speed coupled to the engines with AFM/DFM. Here it is and, to me, it's particularly interesting starting at about the 8 minute mark when he describes the "pendulums". GM 10L80 and Ford 10R80 Torque Converter Operation and Diagnosis

What seems odder, given the symptoms you described, is that they didn't replace the fuel level sensor the first time. Regardless, glad you were able to get it sorted out.

The larger tires shouldn't be an issue for SC to work, but they could throw off the speedo. If the new tires are about the same diameter as the originals the speedo will be close. If the new tires are a size that could have been installed as a factory option the truck can be reprogrammed for that size tire, but I've read not all dealers will do it. Use a tire size calculator. Input the size that the truck came with and the size you want to use. The calculator will show you the difference in diameter and % difference. Tire Size Calculator Forgot to add, installing larger diameter tires without reprogramming the computer may void your warranty. The speedo will be off as will be the odometer - basically under reporting how many miles have been driven.

A technician won't know until they open it up, but if your truck is still under warranty installing that kit will void the drivetrain warranty.

Mine is fixed. Although I took it in on 12/01 the dealer wasn't able to diagnose it until 12/10, and dealer called on 01/13 advising it was ready, so just over a month. As I posted before, below are the actions I took: Opened a case with GM Customer Care via email. [email protected] 12/12/24 Opened a case with NHTSA, since a failing/failed transmission has the potential of being a safety issue. 12/12/24 Opened a case with the Better Business Bureau's "Auto Line" service. 01/06/25 Posted on GM's Facebook page. 01/09/25 I don't know if any of the above helped. I do know as soon as I completed opening the case with BBB on 01/06/25 I received a call from the GM Customer Resolution Center (I believe that's what they called themselves) the very next day. I also know that when the service advisor called on 01/13 to tell me it was ready, and I told him I was surprised, he said something like "I guess the squeaky wheel gets the grease". I don't know if that means GM expedited the part and the repair for my truck ahead of others at the same dealer or if it was just a coincidence. If the former I have to admit I feel a little bad that my incessant whining got my truck fixed before others that were waiting for the same part for as long, or longer, than mine.

Did the check engine light come ever come on? If it did the code is probably stored.

Mine started having problems the moment that message appeared, and the trans was obviously not shifting correctly.

Sorry for the bad news, Frankie, but mine - and evidently many others, failed in much warmer temps. See this thread.

I don't think anyone on this forum has the answer to that question, Sandy, surely someone in GM knows but they are not sharing. You could try reaching out to GM Customer Care and opening a case with them. As well, try the BBB Auto Line. BBB AUTO LINE

Thanks for posting the P/N's, Stan. I trust it's working properly now. Last update I had from the dealer was on 01/02, still no ETA for the VB. Relayed that to GMCS, who replied promptly and thanked me for the update. GMCS, while kind and sympathetic, has not been able to move the ball forward. Yesterday I opened a case with BBB's "Auto Line" service. We'll see. Dan

How long ago where the VB's replaced, Jim? How long did both repairs take from failure to replacement? Do you have the VB part numbers that were used from the paperwork of both repairs?

Fingers crossed for ya, Stan. Has been 21 days since mine was diagnosed as needing a VB. While not nearly as long, yet, as you and others have been waiting it's still way too long. Dan

FWIW, on a typical 1500 with the 10 speed trans the rear end gear ratio is 3.23:1. Meaning for 1 complete revolution of the wheel/tire the driveshaft spins 3.23 times. A driveshaft vibration will be at a higher frequency than a wheel/tire vibration. Another possibility is driveline angle. The transmission output shaft angle needs to be roughly equal to, but opposite of the rear axle pinon angle. If you can find a driveline specialist shop they'd be able to check both the DS for balance and the driveline angles.

Which transmission does your 1500 have, Sandy, the 10 speed? If the 10 speed, you know about as much as the rest of us do, it appears GM has not provided anyone (consumers or their own franchise dealers) with an ET of when these valve bodies might be available. Given that GM continues to manufacture 1000's of new vehicles, every day, with the 10 speed transmission, and all those new builds of course require a valve body, it certainly appears to us owners that GM is prioritizing new vehicle sales for dealer stock and customer orders over providing replacement parts for current owners. While perhaps not surprising, since GM makes no money on replacement parts covered under warranty, it is incredibly frustrating for existing owners.