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AFM Vibration - now with new heavier shudder

14silverado4.3

By 14silverado4.3
in Engines & Drivetrain

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14silverado4.3 Enthusiast

14silverado4.3

Posted
Posted

Hi all, I am familiar with AFM vibration however this is a new twist.

 

4.3 / 4WD / 3.42 gears

 

I have noticed over the last several months the following on Highway cruise mostly

 

1. 74 MPH downhill, cruise control on - on top of the regular low resonance vibes from AFM, I am getting a cycled vibration. It is heavier and comes on for 3-5 seconds, then off. Repeats 4 times on a 1/2 mile down hill grade.

 

Feels like small speed bumps

 

 

2. The other issue I have is when in AFM transitions from V4 to V6 during low throttle input, heavy vibration, it almost feels like torque converter issues.

 

 

Been to dealer, this is normal. I don't think it is but want some ideas from the all knowing GM-Trucks congregation...

I would like to go back to the dealer with a PIP if there is one.

 

Has anyone experienced this and what was the outcome?

 

Fishbait Enthusiast

Fishbait

Posted
Posted

My 2015 6.2 8 speed exhibited those very same issues. The dealer replaced the torque converter and that fixed the problem. So far I have put 3500 miles on the new torque converter and the truck runs and shifts smoothly.I would go to a different dealer if that is an option.

14silverado4.3 Enthusiast

14silverado4.3

Posted
  • Author
Posted

My 2015 6.2 8 speed exhibited those very same issues. The dealer replaced the torque converter and that fixed the problem. So far I have put 3500 miles on the new torque converter and the truck runs and shifts smoothly.I would go to a different dealer if that is an option.

Thanks, I will see what I can do.

Donstar Senior Enthusiast

Donstar

Posted
Posted

You describe very specific situations which I don't know for certain if this will happen in my truck. I can tell you that I have the same power combination as you and the only indication I have of a switch between V6 and V4 is the notification in the DIC. My guess is that if you can feel the switch under any conditions that it is not normal!

FishinJ Enthusiast

FishinJ

Posted
Posted

My 2015 6.2 8 speed exhibited those very same issues. The dealer replaced the torque converter and that fixed the problem. So far I have put 3500 miles on the new torque converter and the truck runs and shifts smoothly.I would go to a different dealer if that is an option.

 

Had the same exact thing and it's been smooth since the replacement.

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