ACF & 6 Speed

[conductor79]

Have a 2011 GMC Sierra with 5.3. I have had this vehicle since Jan 2012,new. This thing drives me crazy with jumping into the V4 AFM! I get a vibration, and it goes into the AFM V4 at 25MPH! I have had this vehicle into the dealer like 3-4 times for this. They did reprogram the computer once but it still drives me crazy! I asked to talk with the dealer rep, but the dealer has never contacted me since I asked to see him. I`ve owned GMC`s since 1998 (6 of them) The most I have ever heard from GM is, they`ll make a notice on my vehicle in case there is an update on the problems I have. Anyone else have this happen? Thanks
(At highway speeds I don`t notice the vibration)

 

[98trck]

i got that vibration after i installed a flowmaster and have it exit in front of the rear tire
i experimented with different hanger positions no luck
then i started turning the connection at the band clamp at the flex joint
NO more vibration
i have the same truck 2wd

 

[GMC Customer Service]

Hello conductor79,

We are sorry to hear of the concerns you've been experiencing and that you haven't been contacted by your dealership. We'd be happy to look further into this and contact your dealership on your behalf. If you'd like our assistance, please send us a private message with your VIN.

Thank you,

Andraya R.
GM Customer Care