AFM Noise/Vibration at Highway Speeds

Marshall_13 · November 30, 2020

I have seen many other threads with this similar issue but different circumstances so I thought id post mine to see if gm has found a fix.

I have a 2018 silverado 5.3L with the 6-speed transmission. The truck only has about 16,000 miles on it and is still under warranty. The problem just recently started within the last few thousand miles or so but when traveling on the interstate between 78-82 mph and goes into v4 mode the truck makes a shuddering noise (not sure what else to call it) and there is a slight vibration in the steering wheel. Its honestly not that bad but it doesn't do it at any other speeds when in v4. Once back into v8 its totally fine and smooth. It doesn't do this at any other speeds just that range. I know the range afm disabler fixes this and I will likely purchase this in the future but would like to see if there is a fix the dealer can do since the truck still is under warranty and has low miles. Id like to see if anyone else had this issue and if it was fixed by the dealer.

I live in Nebraska and have taken all my GM trucks to Sid Dillon Chevrolet and they have always been great to work with and have gone above and beyond to fix problems but Id like some more information from other owners before I take it in and complain.

Thanks!

JimCost2014 · November 30, 2020

2 hours ago, Marshall_13 said:

I have seen many other threads with this similar issue but different circumstances so I thought id post mine to see if gm has found a fix.

I have a 2018 silverado 5.3L with the 6-speed transmission. The truck only has about 16,000 miles on it and is still under warranty. The problem just recently started within the last few thousand miles or so but when traveling on the interstate between 78-82 mph and goes into v4 mode the truck makes a shuddering noise (not sure what else to call it) and there is a slight vibration in the steering wheel. Its honestly not that bad but it doesn't do it at any other speeds when in v4. Once back into v8 its totally fine and smooth. It doesn't do this at any other speeds just that range. I know the range afm disabler fixes this and I will likely purchase this in the future but would like to see if there is a fix the dealer can do since the truck still is under warranty and has low miles. Id like to see if anyone else had this issue and if it was fixed by the dealer.

I live in Nebraska and have taken all my GM trucks to Sid Dillon Chevrolet and they have always been great to work with and have gone above and beyond to fix problems but Id like some more information from other owners before I take it in and complain.

Thanks!

Maybe your torque converter is going bad?

Shudder, driving over "rumble strips", are the most common signs that the TC is getting ready to fail.

Marshall_13 · November 30, 2020

11 minutes ago, JimCost2014 said:

Maybe your torque converter is going bad?

Shudder, driving over "rumble strips", are the most common signs that the TC is getting ready to fail.

Appreciate the response! That crossed my mind as well. It only happens around 80 mph and the vibration in the steering wheel is minimal but noticeable, nothing as severe as a rumble strip vibration. It could be just the start and continue to worsen as time goes on and it is the TC which would be on GM to replace under warranty I guess.

JimCost2014 · November 30, 2020

17 hours ago, Marshall_13 said:

Appreciate the response! That crossed my mind as well. It only happens around 80 mph and the vibration in the steering wheel is minimal but noticeable, nothing as severe as a rumble strip vibration. It could be just the start and continue to worsen as time goes on and it is the TC which would be on GM to replace under warranty I guess.

No problem.

Tech can do a ride along and engage the TC, and then dis engage it to see if there is vibration present while engaged with scan tools.

Edited November 30, 2020 by JimCost2014