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Thread: 6R80 Transmission 3->4 shift flare

  1. #1
    Tuner in Training G_Force's Avatar
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    Unhappy 6R80 Transmission 3->4 shift flare

    I'm working on a 2010 Raptor with the 6.2 upgraded with an ATI ProCharger. The 6R80 trans shifts fine in all gears except the 3->4 shift. The shift is commanded and by the time the shift fully completes, it's 1.27 Sec's later. According to the Transmission > Shift Properties > Clutch Fill Time for the 3->4 shift ([ECM] 40224), it was showing 0.5 Sec's from 2000 -> 6000 RPM. The main issue is at 3000 RPM and up, where this flare is noted by a 240 RPM increase. I changed the table from 0.5 to 0.4 Sec's from 3000 RPM and up, but it made no improvement in decreasing shift time. If I noticed any improvement, I would just keep reducing the Clutch Fill Time.

    The Line Pressure Max is set to the factory 150 psi value and during this shift the Line Pressure PID shows 130 psi, so I don't think increasing the Max Pressure will help. I wish I could increase the Line Pressure for this shift, but the Line Pressure Translation Table ([ECM] 41221) makes no sense with Pressure values (across the top of the columns) being 5.0 -> 62.0 psi. What about something closer to 150 psi on the high end of this scale? The left side of the table shows Trans Oil Temps from 5.0 -> 46.5 F. ATI did not alter this table as they were just as baffled by the constraints on this table as I am. Further, the table is populated with fractional values less than 1.000, so how in the world does this corelate to Line Pressure?

    I don't seem to be able to increase Line Pressure, so I need to reduce the shift time. How is this accomplished?

  2. #2
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    ive seen a flare on the 3-4 wind up being a internal issue and needing a trans

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    Tuner in Training G_Force's Avatar
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    Thanks, Bill. Does it help at all to reduce the Clutch Fill Time for the 3->4 shift?

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    if its a internal trans issue then it probably wont help anything

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    Tuner in Training G_Force's Avatar
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    Thanks for your input!

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    No problem at all

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    Tuner in Training G_Force's Avatar
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    Just as a follow-up ...
    I left the Clutch Fill Time set to 0.4 Sec's for the 3->4 shift. But, I thought it couldn't hurt to bump up the Max Line Pressure from the factory set value of 150, to 175 psi, which I had not touched before. The customer reported back to me that the shifting is now good, with no flare! As I stated from my test drives, for the 3->4 shift, I observed 130 psi line pressure and no more, even though the Max value was set to the factory 150 psi. So apparently Ford is using some kind of limitation to the headroom for what it actually uses for high-end value for pressure compared to whatever the Max value is set to; either 20 psi less than Max or a percentage, which in this case would be a factor of 0.86 (most likely load dependent). There probably other math variables involved, but this is my basic understanding without seeing what the full formula is to calculate what line pressure to use. ATI P/C did not alter the Max Line Pressure from the OE factory setting. Thanks again for your help!

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    Senior Tuner veeefour's Avatar
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    3-4 shift issues can be tune related, but sometimes might be related to internal damage or...OSS went south on that shitty lead frame that fails frequently.

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    Yea that lovely pos lead frame lol

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    Quote Originally Posted by G_Force View Post
    Just as a follow-up ...
    I left the Clutch Fill Time set to 0.4 Sec's for the 3->4 shift. But, I thought it couldn't hurt to bump up the Max Line Pressure from the factory set value of 150, to 175 psi, which I had not touched before. The customer reported back to me that the shifting is now good, with no flare! As I stated from my test drives, for the 3->4 shift, I observed 130 psi line pressure and no more, even though the Max value was set to the factory 150 psi. So apparently Ford is using some kind of limitation to the headroom for what it actually uses for high-end value for pressure compared to whatever the Max value is set to; either 20 psi less than Max or a percentage, which in this case would be a factor of 0.86 (most likely load dependent). There probably other math variables involved, but this is my basic understanding without seeing what the full formula is to calculate what line pressure to use. ATI P/C did not alter the Max Line Pressure from the OE factory setting. Thanks again for your help!
    The increased pressure might end up being a temporary fix if the clutches are mechanically worn. Only time will tell now
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    Quote Originally Posted by G_Force View Post
    I'm working on a 2010 Raptor with the 6.2 upgraded with an ATI ProCharger. The 6R80 trans shifts fine in all gears except the 3->4 shift. The shift is commanded and by the time the shift fully completes, it's 1.27 Sec's later. According to the Transmission > Shift Properties > Clutch Fill Time for the 3->4 shift ([ECM] 40224), it was showing 0.5 Sec's from 2000 -> 6000 RPM. The main issue is at 3000 RPM and up, where this flare is noted by a 240 RPM increase. I changed the table from 0.5 to 0.4 Sec's from 3000 RPM and up, but it made no improvement in decreasing shift time. If I noticed any improvement, I would just keep reducing the Clutch Fill Time.

    The Line Pressure Max is set to the factory 150 psi value and during this shift the Line Pressure PID shows 130 psi, so I don't think increasing the Max Pressure will help. I wish I could increase the Line Pressure for this shift, but the Line Pressure Translation Table ([ECM] 41221) makes no sense with Pressure values (across the top of the columns) being 5.0 -> 62.0 psi. What about something closer to 150 psi on the high end of this scale? The left side of the table shows Trans Oil Temps from 5.0 -> 46.5 F. ATI did not alter this table as they were just as baffled by the constraints on this table as I am. Further, the table is populated with fractional values less than 1.000, so how in the world does this corelate to Line Pressure?

    I don't seem to be able to increase Line Pressure, so I need to reduce the shift time. How is this accomplished?
    Generally Shift flares, A typical converter strategy is full apply after the 2-3 shift and no TCC slip during shifts. if you watch the solenoid signal with a scanner and monitor torque converter pressure. If torque converter pressure is above zero when it should not be, that shift will feel like a flare as rpm spins up due to converter slip. As Blackbolt 22 said "increased pressure might end up being a temporary fix if the clutches are mechanically worn."