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Thread: quick hard shift into 4th gear on 6L80

  1. #1
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    quick hard shift into 4th gear on 6L80

    I had the transmission rebuilt. It has extra clutch packs in the 4/5/6 drum. When the vehicle is cold it takes its time shifting from 3 to 4. Within a few minutes though it seems like on partial throttle shifts it just engages 4th way too quick with a little clunk. I looked at the tune and the temperature parameters to see if the pressures or anything change with the warming transmission. Nothing changed. So is this mechanical or can it be fixed with something in the tune? Thanks
    2016 Hellcat Challenger, automatic, black on black with brass monkey wheels

    10.13@ 140 DA 5000 feet
    2.75 pulley, tune, drag radials. 10 percent lower od crank pulley, 1050 ix. off road mid pipe. tune

  2. #2
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    Might have to adjust the oncoming and offgoing pressures with the change in clutches. Post up the tune. I would like to see it.
    2007 Corvette C6 Vert. A6
    LME LS402, Pat G custom cam, ATI 10% OD Damper
    Circle D triple disc 2600, 3.42 Diff
    YSI, 3.0 pulley, ID 1000's
    Alky Control Meth,
    ARH 1 7/8 headers,
    1009 RWHP @ 7000, 817 RWT @ 6000

  3. #3
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    Quote Originally Posted by realcanuk View Post
    Might have to adjust the oncoming and offgoing pressures with the change in clutches. Post up the tune. I would like to see it.
    I think it is mechanical. As long as it holds together for a couple of years I can live with it. It is just a fast short shift with a clunk. It ignores the time I have it set to for a shift on partial throttle.
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    2016 Hellcat Challenger, automatic, black on black with brass monkey wheels

    10.13@ 140 DA 5000 feet
    2.75 pulley, tune, drag radials. 10 percent lower od crank pulley, 1050 ix. off road mid pipe. tune

  4. #4
    Tuning Addict 5FDP's Avatar
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    Increase the shift time back to .2998 for both normal and special, then see what it does.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  5. #5
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    Quote Originally Posted by 5FDP View Post
    Increase the shift time back to .2998 for both normal and special, then see what it does.

    will do later today and report back.
    2016 Hellcat Challenger, automatic, black on black with brass monkey wheels

    10.13@ 140 DA 5000 feet
    2.75 pulley, tune, drag radials. 10 percent lower od crank pulley, 1050 ix. off road mid pipe. tune

  6. #6
    Tuning Addict 5FDP's Avatar
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    Could also be worth it to reset the transmission presets in the tune and kinda have it relearn and see if anything changes.

    That's easy enough to do in the scanner before you start driving.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  7. #7
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    Well I tried adding time to the shift. .2998. It is ignoring the time factor. What is the exact procedure to follow in the scanner?
    2016 Hellcat Challenger, automatic, black on black with brass monkey wheels

    10.13@ 140 DA 5000 feet
    2.75 pulley, tune, drag radials. 10 percent lower od crank pulley, 1050 ix. off road mid pipe. tune

  8. #8
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    Don't see anything very obviously wrong. I would try setting the shift torque factor adder back to 1.00. Some torque management might help.
    2007 Corvette C6 Vert. A6
    LME LS402, Pat G custom cam, ATI 10% OD Damper
    Circle D triple disc 2600, 3.42 Diff
    YSI, 3.0 pulley, ID 1000's
    Alky Control Meth,
    ARH 1 7/8 headers,
    1009 RWHP @ 7000, 817 RWT @ 6000

  9. #9
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    Quote Originally Posted by realcanuk View Post
    Don't see anything very obviously wrong. I would try setting the shift torque factor adder back to 1.00. Some torque management might help.

    I will give that a try tomorrow morning. What is strange on the way home tonight I put her in sport. After she hit 3rd I lifted my foot off the accelerator. It shifted as smooth as butter into 4th. But when I keep my foot on it, partial throttle, it shifts real fast and clunks into 4th.
    2016 Hellcat Challenger, automatic, black on black with brass monkey wheels

    10.13@ 140 DA 5000 feet
    2.75 pulley, tune, drag radials. 10 percent lower od crank pulley, 1050 ix. off road mid pipe. tune

  10. #10
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    Could it be a pressure control solenoid and if so how hard are they to change and cost?
    2016 Hellcat Challenger, automatic, black on black with brass monkey wheels

    10.13@ 140 DA 5000 feet
    2.75 pulley, tune, drag radials. 10 percent lower od crank pulley, 1050 ix. off road mid pipe. tune

  11. #11
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    Quote Originally Posted by CactusG8 View Post
    Could it be a pressure control solenoid and if so how hard are they to change and cost?
    I guess anything possible but I think those normally throw a code if not working right. Did they change out all the small parts in the rebuild... like with a sonnax zip kit....
    2007 Corvette C6 Vert. A6
    LME LS402, Pat G custom cam, ATI 10% OD Damper
    Circle D triple disc 2600, 3.42 Diff
    YSI, 3.0 pulley, ID 1000's
    Alky Control Meth,
    ARH 1 7/8 headers,
    1009 RWHP @ 7000, 817 RWT @ 6000