Rickochet

Did you have your noise repaired or just living with it?

Thanks so much for the information, Byrds8. I have the noise in Park or while driving, especially loud at 2,000-2,500 RPM. According to the TSB, the most applicable condition is this one: Park Transmission Oil Pump Gear Mesh Whine Unlike previous generation HD transmissions (6 speed), the 10 speed Allison model transmission utilizes a (3) spur gear design (driven off of the torque converter) to drive the transmission oil pump. Due to the 3–spur gear design, some transmissions may exhibit a whine noise while in park or driving and may get louder as engine speed or transmission temperature increases. Isolating the whine to the oil pump gears can often be done by replicating the complaint in park and sweeping engine speed slowly from base idle to 2500 RPM. If whine can be reproduced in park, replacement of the transmission front support and/or transmission oil pump often corrects the whine complaint.

Another JR, So true, and thanks for sharing your wisdom! The whine sounds like an old-school radio whine from an aftermarket radio that was installed with a poor ground. Not something that we should expect from an $80,000+ truck. I believe that GM monitors these forums, maybe I will receive a call... Time will tell.

Do you have the TSB or a link to it?

My 2026 Silverado 2500 Hd 6.6 Gasser has the same noise. It is especially prominent at 2,000 RPM's. Everyone I had ride with me asks, "Wow, that turbo sounds mean!" It's embarrassing to say, "Sorry, that's not a turbo, because it doesn't have one. Unfortunately, GM says it's normal transmission noise." They usually respond with, "Wow, I'm not buying a GM truck!!" It's so sad that GM has this attitude on my brand new truck with only 3,000 miles on it, and it made that noise on my test drive and remains today. I'm at the dealership right now to get it checked again. I'm also going to drive another new 2500 HD to see if it makes the same noise. PLEASE NOTE: GM, I am truly disappointed with this type of quality control and customer service.

My 2015 GMC 1500 4x4 with only 24k miles has had the dreaded shake since I purchased it. Been to the dealership numerous times, replaced 2 tires at my expense, replaced driveshaft, swapped tires & wheels with a 2017 Denali and I still have the shake. It begins at 70, and oscillates from shaking so bad it will vibrate bad enough to shake the entire truck.... continues for a .3 of a mile and gradually gets better. It almost disappears for .2 of a mile and then it gradually returns to the horrible shake. The dealership is at loss for the repair. If a GM representative is monitoring this, please advise. If anyone has truly had any luck with repairing the dreaded Chevy Shake... please advise. Thanks!