Blue2Red

It would happen occasionally, and it was very pronounced, exactly like rumble strips. It took me awhile to realize what it was. I starting thinking is was tires, suspension, differential, and even new rumble strips everywhere. Haha. It would have only at cruise, on the throttle, and at around 1500 rpm. Only problem is that the TSB for the 8 speed, not the 6 speed. The flush, which is the fix on that TSB, is like $500 out of warranty. I’m sending mine back in, as there was obviously damage done and the fluid flush can’t repair that

I ended up going to the dealer with a video and armed with the TSB and they ended up doing the fluid flush under warranty. The “rumble strip” sensation went away, however, more odd things started happening. I began getting a subtle rumble, more like a hesitation all the time while accelerating. Once my foot is off the gas, it goes away. I also made a video of the transmission so major rpm after a downshift. I’d accelerate, take my foot off the gas, the rpm would dramatically go down, then up 1000 rpm, then down 1000rpm, then up. This even happened in manual mode, so they were not shifts. I’m going to continue sending the truck in while it’s under warranty. I refuse to pay money for such a piece of shit, and get no response from GM.

I have a 2016 Sierra 1500 6 speed with 54,000 that has developed the commonly described “rumble strip” issue. It feels exactly like driving over highway rumble strips, happens at various cruising speeds, and doesn’t happen while decelerating. The tachometer also wanders up and down 100-200 rpm while cruising. The happens while cruise control is set or not. I see the TSB for the 8 speed, but I have a 6 speed with identical symptoms. any suggestions ?

Hello guys, I know this is an older thread, but I’m having a very similar problem with my 2016 Sierra 1500 6spd, 5.3L. 54,000 miles. At first I thought it was a suspension issue, as it really exactly like I’m driving over rumble strips on the highway, and I also see the tachometer slightly wandering and down while cruising. The problem only occurred while accelerating, which also makes suspension issues less likely. Based on what I’m seeing, the Torque converter or Transmission fluid appears to be the cause of this. Does anyone have any advice on how to approach the dealership with this, so I don’t get the “could not duplicate” response? I drive the car everyday so it’s easy for me to notice it, however a tech will be in the truck for 10-20 minutes, likely low trans fluid temps and I won’t be there to make sure they “witness” it. I appreciate the help.