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Thread: A6 transmission shifting

  1. #1
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    A6 transmission shifting

    I've got a 2014 L86 silverado with the A6 transmission. I have the shifting down almost exactly how I want it, but am still having a little bit of an issue. The initial shift feels great, but once it gets into 2nd, 3rd, and sometimes 4th, under medium throttle, it seems to slip for a couple seconds before actually locking into the gear. Here is my current trans tune Trans Only.hpt. Ive done everything I can think of so far.

    The next step I think I'll take is adjusting the Final - Normal and Final - Special, in the Shift Timing>Upshift>Transition Time section.

    Am I on the right track? Thanks

  2. #2
    Can't see tune cause I'm on the phone. Have you adjusted oncoming pressure presets?

  3. #3
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    I did, but pretty minimally. <20 I believe

  4. #4
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    Quote Originally Posted by Bamba1260 View Post
    I've got a 2014 L86 silverado with the A6 transmission. I have the shifting down almost exactly how I want it, but am still having a little bit of an issue. The initial shift feels great, but once it gets into 2nd, 3rd, and sometimes 4th, under medium throttle, it seems to slip for a couple seconds before actually locking into the gear. Here is my current trans tune Trans Only.hpt. Ive done everything I can think of so far.

    The next step I think I'll take is adjusting the Final - Normal and Final - Special, in the Shift Timing>Upshift>Transition Time section.

    Am I on the right track? Thanks
    I recommend going to discrete shift mode and disable the 2-3. 1 is enabled, 0 is disabled. Next, to firm up the shifts, go the the shift timing tab, then torque adder. These are the tables that add extra shift timing (for comfort). I like to highlight the entire table and multiply by 0.5 for each shift I want firmed up.

  5. #5
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    Quote Originally Posted by Mbrowning View Post
    I recommend going to discrete shift mode and disable the 2-3. 1 is enabled, 0 is disabled. Next, to firm up the shifts, go the the shift timing tab, then torque adder. These are the tables that add extra shift timing (for comfort). I like to highlight the entire table and multiply by 0.5 for each shift I want firmed up.
    Thanks for all the info man, I appreciate it. For the discrete mode, do you leave the 1-2 enabled? If I disable the 2->3 that leaves only the 1->2 enabled and everything else disabled. Just double checking.

    As for the rest, I've already messed with the shift timing, I am in the ~.4000 range for 1->2, .3000 range for 2->3 and 3->4... Do you take even more out of them?

    Again, thanks for the help. I think I have a very specific issue that I can't figure out, where when it first engages the next gear it slips for far too long.

  6. #6
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    Quote Originally Posted by Bamba1260 View Post
    Thanks for all the info man, I appreciate it. For the discrete mode, do you leave the 1-2 enabled? If I disable the 2->3 that leaves only the 1->2 enabled and everything else disabled. Just double checking.

    As for the rest, I've already messed with the shift timing, I am in the ~.4000 range for 1->2, .3000 range for 2->3 and 3->4... Do you take even more out of them?

    Again, thanks for the help. I think I have a very specific issue that I can't figure out, where when it first engages the next gear it slips for far too long.
    I touched up your file to give you some stuff to look at. I learn a lot looking at changes and researching the definitions and noting changes. The changes I made are the same ones I use in my 2017 Z71. 20,000 miles and 33 inch tires so far no problems. I hope this helps steer you in the right direction. Some of the guys on here are a bit salty. I had a bad experience yesterday just because I asked a question the wrong way. Good luck sir!
    Attached Files Attached Files

  7. #7
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    Quote Originally Posted by Mbrowning View Post
    I touched up your file to give you some stuff to look at. I learn a lot looking at changes and researching the definitions and noting changes. The changes I made are the same ones I use in my 2017 Z71. 20,000 miles and 33 inch tires so far no problems. I hope this helps steer you in the right direction. Some of the guys on here are a bit salty. I had a bad experience yesterday just because I asked a question the wrong way. Good luck sir!
    I appreciate you taking the time to do that man, thanks! That's exactly how I've been doing it, just looking at a bunch of different tunes and trying little changes here and there. I was trying to mess with the Driver Demand tables the most at first, trying to get a really sensitive throttle but it ended up just screwing things up lol. I'll download this one and see what kind of stuff you've changed. Thanks again.

  8. #8
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    Quote Originally Posted by Bamba1260 View Post
    I appreciate you taking the time to do that man, thanks! That's exactly how I've been doing it, just looking at a bunch of different tunes and trying little changes here and there. I was trying to mess with the Driver Demand tables the most at first, trying to get a really sensitive throttle but it ended up just screwing things up lol. I'll download this one and see what kind of stuff you've changed. Thanks again.
    On the driver demand tables, highlight the WHOLE TABLE and multiply by 1.1. Tables A and C are the ones to modify.

  9. #9
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    Quote Originally Posted by Mbrowning View Post
    On the driver demand tables, highlight the WHOLE TABLE and multiply by 1.1. Tables A and C are the ones to modify.
    That?s where I am at right now. I?ve played around a whole bunch, going to 1.5 and trying just in different sections, etc.. 1.1 is about as good as it gets lol.

  10. #10
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    You can get in trouble quick with those tables. That's why they warn you to change them at your own risk. If you increase the ENTIRE table by 5 or 10 percent. It makes the entire vehicle react quicker AND takes the throttle lag out. You get all of this with the added bonus of not having to deal with throttle closures at high rpm pulls. You will notice your negative numbers go deeper negative as well. This is what you want. Marshall