Valve Body Replacement - 2023 Silverado Custom Trail Boss

Ed Do · April 24

I have 2023 GMC Sierra 1500 Denali. It was purchased in June of last year. It stuck in 5 gears, and currently at my local dealership awaiting for valve body.
I planned to buy this truck to pull my boat but has transmission issue one week prior my new boat arrived at the dealership.
im very frustrating not knowing when will it be repaired because fishing season has started in New England right now.
i should have bought Toyota when I had a chance!!!

GMCustomerService · April 24

11 hours ago, Ed Do said:

I have 2023 GMC Sierra 1500 Denali. It was purchased in June of last year. It stuck in 5 gears, and currently at my local dealership awaiting for valve body.
I planned to buy this truck to pull my boat but has transmission issue one week prior my new boat arrived at the dealership.
im very frustrating not knowing when will it be repaired because fishing season has started in New England right now.
i should have bought Toyota when I had a chance!!!

We regret to hear that you are facing these challenges with your Sierra and would like to take the opportunity to learn more. To do so, please send us an email to [email protected]. Be sure to include your Username and Forum name in the subject line with additional details. We look forward to your email.

DMAX 23 · April 25

New here. I purchased my 23 Sierra 3.0l with the 10 speed end of Jan. 2023. I put 53k on it so far, 90% highway miles and I am also having valve body issues. Been in the shop 3 weeks now since they can’t get the part. Spoke with the Service Manager yesterday and he mentioned if they can’t find a part soon he will put in a request to replace the entire transmission. Hoping this doesn’t take to much longer.

Bikerjon · April 25

6 hours ago, DMAX 23 said:

New here. I purchased my 23 Sierra 3.0l with the 10 speed end of Jan. 2023. I put 53k on it so far, 90% highway miles and I am also having valve body issues. Been in the shop 3 weeks now since they can’t get the part. Spoke with the Service Manager yesterday and he mentioned if they can’t find a part soon he will put in a request to replace the entire transmission. Hoping this doesn’t take to much longer.

Welcome to the forum. New trans would be great for you and would put pressure on GM to get this valve body supply issue straightened out. There are others waiting for backordered valve bodies.

Cayenneguy · May 8

On 4/18/2024 at 1:00 PM, Cayenneguy said:

I've owned a 2023 GMC Sierra Elevation 2.7L 4 cyl for less than one year. It's been in the shop three times and its currently in the shop once again due to a transmission issue. I hear a big bang in the transmission while stopped at a light and then check engine comes on and the truck is stuck in one gear only. Its been in the shop almost 10 weeks in less than one year of ownership. The dealership is working with the GM tech line and they are waiting for a valve body part which is currently in back order status. Getting VERY frustrated right now !!! This truck is for work and the dealership has been very helpful trying to fix the problem however the problem keeps coming back and I'm almost sure it may fail again.

Truck in the shop since 3/19 and still no solution from GM yet, hoping for a repurchase at this point.

Jeremy1112 · May 8

2020 Sierra 2500 HD been dealing with same issue for 8 months. Dealership has basically put in 4 new valve bodies 1 being whole new transmission one being whole new transfer case. Truck still not fixed now they are putting in the 5th new valve body that has supposedly been redesigned. But it’s on back order so disappointing that GM is putting out such a poor product time to stop giving them my money they just don’t care and don’t make quality trucks anymore.

Edited May 8 by Jeremy1112

Becbec · May 10

Hi guys, I bought a 2023 duramax with 24k miles. I drove it once and it broke down with transmission problems it was diagnosed that it needs a new valve body as well. The dealership is very vague with timelines and such but like a lot of you this truck is for work and I don’t have 3-4 months to make payments on it and not be driving it. Has anyone had experience getting it fixed not by a dealership or selling it for something else? I’m at a loss and very frustrated this is a huge investment to go this bad this quickly. Thank you all for any advice

GMCustomerService · May 14

On 5/10/2024 at 9:18 AM, Becbec said:

Hi guys, I bought a 2023 duramax with 24k miles. I drove it once and it broke down with transmission problems it was diagnosed that it needs a new valve body as well. The dealership is very vague with timelines and such but like a lot of you this truck is for work and I don’t have 3-4 months to make payments on it and not be driving it. Has anyone had experience getting it fixed not by a dealership or selling it for something else? I’m at a loss and very frustrated this is a huge investment to go this bad this quickly. Thank you all for any advice

We are sorry to see you are having transmission concerns with your vehicle and would like to take the time to learn more. To get started, please send us an email to [email protected]. Be sure to include your Username and Forum name in the subject line with additional details. We look forward to hearing from you.

Shannon23denali · May 14

16 hours ago, GMCustomerService said:

We are sorry to see you are having transmission concerns with your vehicle and would like to take the time to learn more. To get started, please send us an email to [email protected]. Be sure to include your Username and Forum name in the subject line with additional details. We look forward to hearing from you.

I bought a 23 2500denali with 38k just last week out of state. Beautiful truck ! Got 1 hour away from dealership and trany shifted hard light came on with reduce speed warning. Limped back to a local dealership and had a valve body installed. Had to stay 2 extra nights in a hotel. But that was alright if that fixed the problem. 400 miles later I felt a shudder and 200 miles after that another shudder and the light came back on. 2 1/2 hours away from home on I-5. I drove it home hoping the transmission would explode and get a new one. Not so lucky. I have and appointment for Thursday at the local dealership. I had him pull the code and it wasn’t transmission related I’m driving it around town and it still shudders at certain times. It sounds like it’s a fairly common issue. What a shame !

esteeg · May 17

Having the same issue with my 2023 GMC Sierra 1500 AT4. 14k miles and have had issues with hard shifting and shuddering at lower speeds. This past weekend my truck stalled while turning onto a highway and starting rapidly hard shifting between gears without giving me any power to accelerate. Fortunately there were no cars coming, but it could've resulted in a bad accident otherwise. The check engine light came on and then I saw the reduced acceleration / limp mode get enabled (codes P0700 and P0747 according to OnStar diagnostics). I tried restarting the truck, but it was still in that mode. Was able to get it to the dealership and was told the valve body and other parts need to be replaced but are on backorder. I'm behind several other people at this dealership needing the same part, and there is no ETA for the parts. I'm extremely disappointed after spending more money on this truck than I thought I ever would, only to have it break down without an end in sight within the first 6 months. Aside from these issues, I have loved this truck. It was my first GM vehicle, but it will likely be my last. My biggest concern is that this issue is just the beginning of continued issues based upon what I'm reading from others. Has anyone had success with a buyback or a transmission fix that solves the problems long term?

Edited May 17 by esteeg

Linq · May 17

I have a 2023 Silverado 3500HD SRW - 10 speed Allison Diesel.. 40K km's on it, just encountered the same issue. Being told by dealer unknown when the valve body will be available. Suggested I get a rental.. cause ya who can afford that after paying nearly $100K FOR A VEHICLE.. Have been a GM person by default my whole life - as my father worked factory for 33years, but growing more and more disappointed, with product, dealerships etc... Could be saying goodbye to my camping season...

GPplumbing · May 20

I have a 23' GMC 2500 AT4 with 34,000 miles on it and am having the same issue. The truck has occasionally had some hard downshifts at slow speed approaching red-lights and such since brand new. A few weeks ago while hauling my 43' 5th wheel, the truck attempted to down shift on the highway around 65mph for a slight incline and it was VIOLENT. Felt and sounded like the transmission just fell out of the truck. Made it to the lake and spent the weekend. A few days after being back home the truck stumbled trying to shift leaving a parking lot, went into limp mode and threw P0747.

Truck has now been at the dealership since 5/6 waiting on the backordered valve body with no ETA available, I was told to wait patiently and they will call when it's done. This is completely unacceptable for a $100k truck. I own a plumbing company and just recently decided to upgrade my fleet with some brand new GMC 2500 utility body trucks, which I am now regretting.

Making $1,650 payments on a truck that I may be without for months is ridiculous. My summer is now also shot as I have no way to haul my boat, or 5th wheel anywhere without purchasing another truck.

Seriously considering switching to Ford for my personal and fleet vehicles.

GMCustomerService · May 20

7 minutes ago, GPplumbing said:

I have a 23' GMC 2500 AT4 with 34,000 miles on it and am having the same issue. The truck has occasionally had some hard downshifts at slow speed approaching red-lights and such since brand new. A few weeks ago while hauling my 43' 5th wheel, the truck attempted to down shift on the highway around 65mph for a slight incline and it was VIOLENT. Felt and sounded like the transmission just fell out of the truck. Made it to the lake and spent the weekend. A few days after being back home the truck stumbled trying to shift leaving a parking lot, went into limp mode and threw P0747.

Truck has now been at the dealership since 5/6 waiting on the backordered valve body with no ETA available, I was told to wait patiently and they will call when it's done. This is completely unacceptable for a $100k truck. I own a plumbing company and just recently decided to upgrade my fleet with some brand new GMC 2500 utility body trucks, which I am now regretting.

Making $1,650 payments on a truck that I may be without for months is ridiculous. My summer is now also shot as I have no way to haul my boat, or 5th wheel anywhere without purchasing another truck.

Seriously considering switching to Ford for my personal and fleet vehicles.

We are sorry to hear of about these challenges you are facing with your vehicle and would like to take the opportunity to learn more. To get started, please send us an email to [email protected]. Be sure to include your Username and Forum name in the subject line with additional details. We look forward to your outreach.

Tom73 · May 23

Reading the above posts is not making me feel good. Have a ‘22 Sierra Limited, 6.2 10 speed, 50k miles. At the recommended of the dealer and users here I took it in for routine transmission service (fluid and filter). They finished and it would not go into reverse. Diagnostic says bad solenoid in the valve body. They trying to find a replacement valve body but so far no luck. Has been a week. What is irritating is that I was not having any problems. Take it in for preventative maintenance, not required maintenance, and it breaks.

Edited May 23 by Tom73

Michael Lung · May 23

Man, this thread really took off. Sorry to hear about everyone having similar issues as I did. I’m about 5000 miles into my new transmission and it’s still running fine *knocks on wood*. Keep pressuring your service managers for new transmissions (with the new part numbered valve body)…just a valve body order seems to just leave you without your truck for months. And I’m sure we can all agree, that is just unacceptable.