2024 Chevrolet Silverado 3500

The Engine Cooler has a know defect that GM has put out service bulletins for. The engine cooler is cracking, mixing oil and antifreeze that is creating a sludge that runs thru the entire system. GM wants techs to attempt to clean/flush the engine before they approve a new engine to be ordered under warranty. GM is aware of the problem and there should be a recall out on the problem according to the service manager I spoke with at the dealership my truck is at currently. I was told the expected time frame is up to 3 months for the work to be completed, with no loaner available that is equivalent to the vehicle that went to the shop. The recall is necessary because if the engine has a major failure while driving it could cause an accident, if the vehicle is hauling a heavy trailer that could be detrimental because the truck can haul up to 40,000 GCWR.

REAR WHEEL LOCKUP: While driving down the highway pulling a loaded trailer the rear wheels locked up, GM has an open recall on 2020-2022 models but denies its an issue with the 2024 model, my dealership pushed a “software update” but that does not fix the faulty transmission valve body issue, it just overrides the safety features that were designed to protect the transmission. I have a video of it occurring while slowing down for a stop sign when it did it the second time to me.

The engine oil cooler failed causing engine oil to leak into the coolant system on my 2024 Chevy Silverado 3500HD. This requires a full replacement of the coolant system. In addition, excessive sludge buildup inside the motor is caused. This is a known issue with GM for 2024 Diesel vehicles. GM has released a service bulletin but is fighting my local dealership on the required repairs.

NHTSA Vehicle Safety Complaint I am reporting a serious transmission defect in my 2024 Chevrolet Silverado 3500HD LT that creates a high risk of sudden power loss, erratic shifting, or loss of control while driving. Vehicle Details: - Make/Model/Year: Chevrolet Silverado 3500HD LT, 2024 - VIN: 2GC4YTEYXR1263768 - Engine: 6.6L Duramax diesel - Transmission: 10-speed Allison (10L1000) - Mileage at diagnosis: ~46,000 miles - Title: Rebuilt (warranty denied due to branding) Defect Description: The transmission shifts normally when cold (fluid below ~138°F). Once warm (during normal driving), it fails to upshift properly in gears 5-8: holds lower gears, causes high RPMs (3,000+), delays shifts excessively, or refuses to shift. When shifts occur, they are hard and jerky. Automatic (Drive) mode is affected; manual/L mode works normally as a workaround. No warning lights appeared initially, but the issue has worsened and is now frequent at operating temperature. Diagnosis: On January 28, 2026, Seminole GM (1405 N Milt Phillips, Seminole, OK 74868; 405-382-6130) diagnosed a defective valve body requiring replacement. Quote: - Valve Body Control Module (Part #24065357): $687.48 - Transmission Fluid (12 qt @ $10.92): $131.04 - Labor (diagnosis + pan/filter/relearn): $805.50 - Supplies/taxes: ~$140 - Total: $1,763.94 Dealer confirmed this is a common issue; photos of quote available for upload. Safety Risks: At highway speeds, delayed/no upshifts can cause: - Sudden inability to accelerate (merging, passing, hills) - Harsh engagement leading to wheel slip or loss of control - Potential limp mode entry, stranding in low gears This intermittent warm-only failure is unpredictable and dangerous. Context: This matches widespread complaints on 2023-2025 GM HD trucks with the 10L1000 (forums: DuramaxForum, Reddit r/Duramax/r/Silverado, GM-Trucks.com), involving valve body wear/pressure loss. Earlier years had related recalls (e.g., NHTSA 24V-797 for valve issues),

I was driving on the interstate at around 65mph. Towing my fifth wheel. Transmission started shifting hard with a loud bang that sounded like we hit a huge pothole. A message popped up in the screen indicating “Reduced acceleration, drive with caution”. The transmission seems to be stuck in gear as we exited the highway. Check engine light was on. Came to a stop at a stop sign and barely had enough power to pull into a parking lot. We had the truck towed to a nearby dealership. Fault codes P0700 and P0747 were present. Service advisor said valve body would have to be rebuilt. It’s been 2 weeks and the valve body cover plate is still “backordered” with no estimated in stock date.