2011 Sierra 5.3 6spd - shudder/heavy vibration under light accel after coasting

Knowles Richard

New member
Joined
Apr 5, 2018
Messages
12
Reaction score
0
Points
0
Hello Double D & truckers I have a 2013 gmc sierra sle 5.3 SL80 transmission by putting the trans in (M) mode on shifter And then pressing the toggle switch to 5th gear This disables the AFM or v8/v4 so that its all the time v8 My truck also stays in all time v8 when in tow haul mode But its not good city driving RPMs to high on up shifts Eats Gas I got a diablo P2 and deleted that Stinking AFM. Weird exhaust noise GONE vibration GONE.Much Better performance I am happy that's how it worked for my truck hope this helps
 

GregNH

New member
Joined
Apr 3, 2021
Messages
3
Reaction score
0
Points
1
I have a 2011 Denali 6.2 that does not have AFM but I have the shudder when trying to slightly press gas at highway speeds mostly. I have seen this Service Bulletin but again it states AFM and I don't have that. https://static.nhtsa.gov/odi/tsbs/2015/MC-10113542-9999.pdf

Seems like GM is having people PM them but no solution is being posted. The part in the SB does not fit my tranny anyway according to one site.
 
Top