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2012 Silverado transmission not impressed

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by vtx1800sba, Jun 27, 2013.

  1. vtx1800sba

    vtx1800sba New Member

    Guys and Gals. I bought a 2012 Silverado last year, crew cab 5.3 with the 6 speed auto. I am quite disappointed with it. This thing lugs when accelerating from a slow speed, hunts for gears in traffic, etc. I put it in manual mode just so it'll shift right when driving in town. To get it into passing gear on the highway I have to dick around with the gas pedal or stomp on it to shift up. No codes coming up when I take it for oil change, and the dealership says "hay we can't find anything wrong". My 1996 tahoe (only 75k miles on it) shifts so much tighter and better than this 2012. Only thing I've done to the truck is put a Volant cold air intake kit on it. It has increased overall power but anemic tranny remains. Any advice?

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  2. shibby2oo8

    shibby2oo8 New Member

    If you dont like the shift points get a tune. Right now fuel econ is the main thing so that trans will keep the engine at low rpms as long as it can.
  3. stchman

    stchman New Member 1000 Posts

    My 2013 feels slightly slow unless I push the pedal down. I'm used to it and it looks like GM want to keep the PRMs down as much as they can for fuel economy. I'm used to it, and I like that I'm getting combined ~19MPG.

    You can get hand held tuners that you can modify shift points if you wish, just know that your fuel economy will probably suffer.
  4. j cat

    j cat Active Member 1000 Posts

    what to do is get the NON AFM engine. no one with the 1999-2006 vehicles have this issue.

    I am sure you already were told by the dealership service manager that " THEY ALL DO IT ".

    I know of a company that purchased a fleet of 6 cyl vehicles just because of these issues you have. prior to that they had the 5.3 L NON AFM ENGINES.
  5. steved

    steved Former Member


    I asked about the low RPM shifts and holding gears too long, I was told it was a reprogramming of the TCM because there were so many complaints regarding too much shifting in the previous versions. I asked this at the dealer I bought the truck from and the local dealer, just to verify...same answer from both. I sometimes wish mine shifted sooner than it does, but as for driveability; I have no other complaints...but its also not an AFM.

    One thing to keep in mind is they aren't a car...as much as we want them to behave like a car, drive like a car, handle like a car...
  6. tbplus10

    tbplus10 Super Moderator Staff Member Platinum Contributor 1000 Posts

    Have you tried running the trans in tow mode?
    Some dealerships recommend trying that vs getting a tune that may or may not void warranty.
    In tow mode the trans will shift at higher rpms and has a more crisp shift.
    The Hydramatic 6L80 is designed to automatically upshif if you mash the pedal and hit 5500rpms.
    But like posted the main design of this trans in any application (AFM or Non AFM) is to reduce fuel consumption by keeping engine rpms low and making use of energy already spent by coasting, notice they dont do a real good job with engine braking?
    The GM powertrain site can give you better specifics on the engine trans capabilitys.
    http://gmpowertrain.com/VehicleEngines/PowertrainProducts.aspx
  7. Earl9250

    Earl9250 New Member

    I bought Diablosport Intune for my 2012. I used it to turn off the AFM and retune the Transmission Control Module. It drives much better now, a whole lot closer to my 2005, than it did before.
  8. adampaul1964

    adampaul1964 Active Member ROTM Winner 1000 Posts


    X2 on tow mode, I drive my '05 in tow/haul most of the time until I hit the highway. Gas mileage suffers but I don't really care, its a truck.
  9. CKNSLS

    CKNSLS Member

    You can fix this with the Range Technology "black box". It's a shame one has to spend $200.00 but those who purchased it have really been satisfied.
    www.rangetechnology.com
  10. JimmyA

    JimmyA Member

    I purchased a SCT tuner (gm specific) http://www.sctflash.com/ and turned off the AFM. I normally drive in Tow mode and am slightly happy but a Gear Change will be the kicker for me. Yep the Tranny is the weak link to me being a happy driver of a stock gm truck.

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