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Thread: Allison AL5 Shift Parameters

  1. #1
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    Default Allison AL5 Shift Parameters

    Can someone explain the part throttle shifts to me. I have a few questions.
    Why is Table B (4low) roughly the same speeds as the rest. Wouldn't 4 low be much lower. I read in a post from years ago that table B and D are switched. Is this true.

    I am trying to take out the delayed 5-4 shift. Nothing seems to change the way it downshifts. Example 4-5 upshift I moved KMH down roughly 20%. Then 5-4 downshifts I have 4KMH lower than those speeds. Truck still needs 70% throttle or better to shift. Lets say the truck shifts into 5th at 50mph. Then after it shifts I start pressing the throttle going up a hill. Truck is doing maybe 55mph. Takes almost 75% throttle until it shifts 5-4

  2. #2
    Lifetime Member THEFERMANATOR's Avatar
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    The 4 low and tow haul tables are reversed. This has been brought up SEVERAL times. Those of us who mess with them just know which one is which. I've also found a pretty big glitch in the 02 OS where the 4-5 shift in tow haul is 5MPH different than what is in the table. And there are THOUSANDS of tables in the TCM we CANNOT see with EFILIVE, so BEWARE making ANY changes. A change to a table we have access to can change a few dozen tables we DON'T have access to(or even can see), and can cause SERIOUS transmission damage. For the most part I have found what we have access to only really works well for adjusting half throttle and up shift tables. It is all that 95% of the people adjusting the shift points want/need to adjust, so it works for the majority. For the rest of us, we just have to work around it as best we can, we can't expect the folks at EFILIVE to spend HUNDREDS of man hours breaking down code in the TCM to make changes that only a few people really need to make. Those with the software to really dive into tuning in them can't because of legal reasons from the GM sale of ALLISON, so be thankfull for what we do have.
    1995 GMC 2500 SUBURBAN powered by 01 DURAMAX/ALLISON, little of this, a little of that,
    DIAMONDEYE 4" exhaust, CORSA muffler, AFE stage 1 dry filter, custom tuning by me, KENNEDY single pump and pump rub kit.

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    What I want seems fairly simple. When towing, I'm going down the road, increasing speed and in 4th gear, not much throttle. At 50 MPH at hardly any throttle I want the truck to shift into 5th. It just hangs in 4th until I go a little faster. I hate it. Then once I'm in 5th, I want it to downshift when I push the pedal down. It doesn't shift until 755 or more throttle. I hate it. Now that I know the tables are reversed, this should be easy. I modified all my TAP's and TAV's. It shifts super smooth now. I always had a slight hang up in 3-4. Decreasing by 200ms really made that shift nice. I have a Transgo JR and it always made the 3-4 harsh.

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    Lifetime Member THEFERMANATOR's Avatar
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    Hate to burst your bubble, but as soon as you let off the throttle, it's going to pop back into 4th gear, and will be SLOW to go back into 5th gear. We do not have access to the closed throttle tables, so no matter what you put in at 0%, it may or may not work. Also depending on the year you're working on, the speeds in the table may be mismarked. So don't be surprised if it doesn't respond. I've heard from others that teh LLY tune responds better than teh LB7 does to changes, but the early OS's don't like to listen.
    1995 GMC 2500 SUBURBAN powered by 01 DURAMAX/ALLISON, little of this, a little of that,
    DIAMONDEYE 4" exhaust, CORSA muffler, AFE stage 1 dry filter, custom tuning by me, KENNEDY single pump and pump rub kit.

  5. #5
    Lifetime Member Chavez91's Avatar
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    Ill keep an eye out for closed throttle tables. I've been digging through the AL5s while I wait for my T87 to show up. Specifically the 15196784 OS. Ill let you know if I ever come across anything and test it successfully.
    Josh

    '04 GMC LLY
    - L5P, Motech, 6-Spd Conv. ML Trans.
    '05 GMC LLY - 250%, 12mm, 67mm Custom Turbo, 6-Spd Conv. ML Trans
    '19 3500 RAM - Tuned Aisin 0_o

  6. #6
    Forum tyhee Site Admin GMPX's Avatar
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    Quote Originally Posted by THEFERMANATOR View Post
    The 4 low and tow haul tables are reversed. This has been brought up SEVERAL times.
    Can you please point me to a thread mentioning this or just let me know what OS this applies to? Thanks.

    Quote Originally Posted by THEFERMANATOR View Post
    And there are THOUSANDS of tables in the TCM we CANNOT see with EFILIVE, so BEWARE making ANY changes.
    That is true and applies to pretty much any controller, I don't think it is reasonable to expect any tuning software to put in 'THOUSANDS' of tables for every user, it would literally takes months and months of work to do that if even possible.


  7. #7
    Lifetime Member Chavez91's Avatar
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    Quote Originally Posted by THEFERMANATOR View Post
    The 4 low and tow haul tables are reversed. This has been brought up SEVERAL times.
    Quote Originally Posted by GMPX View Post
    Can you please point me to a thread mentioning this or just let me know what OS this applies to? Thanks.
    I hadn't heard of this either. But Ill test it for ya this week and if it is a problem, ill let you know what OS's I have that it applies to.
    Josh

    '04 GMC LLY
    - L5P, Motech, 6-Spd Conv. ML Trans.
    '05 GMC LLY - 250%, 12mm, 67mm Custom Turbo, 6-Spd Conv. ML Trans
    '19 3500 RAM - Tuned Aisin 0_o

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    Finally got it. Shifts great now. Up shifts at 50. Downshifts 5-4 at 30% or higher. Stays in 5 when I let off the throttle. Exactly what I wanted. Thanks for letting me know about table b and d being switched. My camper thanks me now.

  9. #9
    Lifetime Member THEFERMANATOR's Avatar
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    Quote Originally Posted by GMPX View Post
    Can you please point me to a thread mentioning this or just let me know what OS this applies to? Thanks.


    That is true and applies to pretty much any controller, I don't think it is reasonable to expect any tuning software to put in 'THOUSANDS' of tables for every user, it would literally takes months and months of work to do that if even possible.
    I know I've posted about the tables being mislabled, as well as the 4-5 shift table before. So far for me anyways, all of the LB7 5 speed OS's have the tables reversed. The pattern B tables are labled as 4 low, but are actually tow/haul, and pattern D is labled tow/haul, and is 4 low. Last I seen posted on it was that you had changed them around, and then somebody said it was backwards for them, so you changed it back and left it. https://forum.efilive.com/showthread...+haul+reversed (theres MANY more threads here and on several of the DURAMAX boards about it) And about the 0% throttle tables not responding, I'm not the only one to encounter it either. https://forum.efilive.com/showthread...+haul+reversed

    The 02 15172881 has a serious glitch in it. Under D5003 pattern B, the tables are labled just like the 01 OS(15175854), but the shifts do not occur there. They occur at the same shift points as the 03-04 LB7 OS(15184109). This was the only table I found this way in it, but it sure had me scratching my head trying to figure out a 4-5 5-4 shift issue after I ran my normal script over it that I use on all the other LB7 TCM OS's.

    And I understand about not having but so many tables. We can't ask you guys to break down and add in tables that only a handfull of us would actually use. It would be nice to have the 0% throttle shift/lockup tables though as it's annoying as all get out driving around town, and everytime I let off the throttle it downshifts at 30MPH, or having my converter unlock whenever I drop below 55 no matter where I set it to stat locked at.
    1995 GMC 2500 SUBURBAN powered by 01 DURAMAX/ALLISON, little of this, a little of that,
    DIAMONDEYE 4" exhaust, CORSA muffler, AFE stage 1 dry filter, custom tuning by me, KENNEDY single pump and pump rub kit.

  10. #10
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    Here's another one when I had trouble with the 4Low and T/H tables being swapped between builds as well. Really threw me for a loop back then I remember.

    https://forum.efilive.com/showthread...son-bug-in-139

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