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Thread: Problem with tranny autostick up-shifting with Jeep Wrangler 2013

  1. #1
    Potential Tuner
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    Mar 2019
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    Problem with tranny autostick up-shifting with Jeep Wrangler 2013

    Jeep Wrangler 2013 4 door 3.6L pentastar engine with 5-Speed Auto W5A580 Transmission. Am contemplating on buying an HP tuner, provided it can solve one very particular problem I am facing. Am currently using a Superchips tuner on the Jeep and canned tunes but this has not solved my problem.

    Here in the Dubai we do desert dune-bashing where we need a lot of high rpms and torque. When climbing some very steep dunes, i put the transmission in autostick mode and set it to 1st gear so that i get maximum torque possible. However the problem is, many a times, especially when the rpms are near 6000+ the transmission will automatically shift to 2nd gear even though I have selected 1st gear. Can we fix this issue with an HP tuner, safely, without bricking the tranny and the engine? Has anybody done this before? If it is possible how do i go about tuning this? Apologies if this is a noob/stupid question; i am new to HP tuners so I will need all the guidance i can get.

    cheers
    Simon
    Jeep Wrangler 2013, JKU, Auto-transmission

  2. #2
    Advanced Tuner
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    Feb 2016
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    You need to lift the trans rev-limit so that it bumps up against the engine rev-limit instead of shifting already.

  3. #3
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    Nov 2018
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    did you find a solution ?

  4. #4
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    Quote Originally Posted by Hemituna View Post
    You need to lift the trans rev-limit so that it bumps up against the engine rev-limit instead of shifting already.

    I agree with you diagnosis.I see three options in front of me to achieve the same.

    Option 1) Increase the TCM RPM limit from the current 6400 to 6800. But i am worried about damage (long term) to the transmission. Should i be worried?

    Option 2) Instead of increasing the TCM RPM limit, I will decrease the Engine rev-limit to 6000 and keep the TCM rev-limit as it is at 6400. As it is, i don't see much increase in HP/TQ above 6000 on my wrangler, so i don't mind the engine rev-limit. Noob question: to set engine rev-limit at 6000, should i change the cutoff or change the maximum? See attached screenshot. Are there other places i will need to set the engine rev-limit?

    Option 3)Disable autostick-upshift altogether. But will the TCM rev-limit override this setting and force it to upshift?

    Which is the best option and why? Or is there another option? Pls correct me if I am wrong since I am newbie.

    regards
    Simon
    Attached Images Attached Images
    Jeep Wrangler 2013, JKU, Auto-transmission

  5. #5
    Advanced Tuner
    Join Date
    Feb 2016
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    1. You won't damage the trans by moving the TCM limit...it is just an rpm limit to prevent the engine over revving in any gear or downshift situation.
    2. You wont damage the engine by raising the TCM limit...we run the boosted 3.6's well past 7k (most shift at 6.8 - 7.3k) with 7.5k engine limit and have not hurt one yet.
    3. You will need to set all the rev maximums to whatever you want as the trans rev limit is the trans rev limit no matter what the mode.
    So manipulate both (engine/TCM) till you get the result you are after.