|01-02-2013 01:42 PM|
I posted this in your other thread:
The OEM 18" tires are slightly taller than 32" and most "33's" are a few tenths under 33". The difference is almost non-existent, a few revolutions per mile.
The transmission determines when to shift based on many factors, including engine speed, throttle position, engine intake vacuum (a function of throttle position and engine load), road speed, and trans. temperature.
The unsprung weight of the tires will have a much greater impact than a few tenths of height. There will be more load on the motor, having to deal with the additional resistance of the extra weight. This means that at the same throttle position as before, intake vacuum will last longer and the motor will therefore rev higher before upshifting. Is this perhaps what you're referring to?
But like I mentioned, it's also adaptive and will learn your driving style over the first 50 warm up cycles. If you have a lead foot, yours will hold the revs longer than mine. If you're inconsistent (light foot some days, heavy foot other days) that's when you might find issue with it. They assume the same person driving the vehicle consistently.
Try resetting the ECU to clear the learning module and then drive it like you normally would to re-program it with your new tires.
|01-02-2013 12:17 PM|
Your right about this being a tuff tranny. Also these are computer contolled transmissions and are very sensitive to throttle inputs and gear & tire changes. One has to be very careful on these upgrades. These V6 engines are high performance but have to be revved to keep in the power band, Some of these jeep builds go from 4200 lbs / 2door to up near 5000 lbs. 4 door with bumpers tires etc. So it confuses the hell out of these things.
|01-02-2013 11:21 AM|
|01-02-2013 11:02 AM|
|01-02-2013 10:55 AM|
Stock Rubicon with 4:10s and mine shifts about the same. Of course, I'm not easy on the gas pedal, especially going from 1st to 2nd. Usually I'm mashing the pedal to speed up quickly.
I don't know if it is coincidence, but my previous Pontiac reacted the same way. Sometimes it didn't want to shift until I lifted my foot off the gas pedal for a brief second. Again, could be coincidental or my imagination.
|01-02-2013 10:47 AM|
|jadmt||I drive a charger at work and it shifts the same way to me. I am not sure if the tranny is the same in the two but they hold up to quantum amounts of abuse. I think it is the same tranny that the 5.7L ram uses. I am guessing the tranny is ok.|
|01-02-2013 03:15 AM|
Yeah ... and if you want to add more to the beast call Paramount.
News « Paramount Performance Products
|01-02-2013 03:00 AM|
|Braveheart12JK||I haven't heard a lot on the longevity of this tranny, but I have heard that it's fairly bulletproof and it can handle plenty of HP and TQ. This would lead me to believe that it has good lasting power....that being said, it is one crazy beast. lol|
|01-02-2013 02:30 AM|
Therefore at this point I'd place my bet on the trans.
|01-02-2013 02:16 AM|
|MikeK46||An auto trans outlasting the motor? That wouldn't say much about the Pentastar.|
|01-02-2013 02:09 AM|
It will outlast that 3.6L its bolted to... it can withstand about 600 HP stock.
|01-02-2013 01:47 AM|
I love my Jeep, but there's a lot of bullshit that goes along with it, more than any other car I've previously owned, including the cheaper ones...
I can't see such an inconsistent transmission lasting 100,000 miles ... How would that be possible when its mood changes by the minute? Lol
|01-02-2013 01:30 AM|
|Braveheart12JK||I agree with the OP. I have a '12 with 33" tires and 4:10 gears now, did the Procal adjust and the tranny still seems to have a mind of its own. Note: it seemed like that with the stock tires and 3:21's too though. Sometimes it shifts crisp and sporty, other times it seems to climb higher into the RPMs before shifting, even under easy acceleration. Hmmmmm|
|01-02-2013 01:00 AM|
|The_Chief||Bump...want more opinions please.|
|01-01-2013 11:25 PM|
|01-01-2013 11:13 PM|
|01-01-2013 11:01 PM|
|01-01-2013 10:57 PM|
|01-01-2013 10:41 PM|
|jadmt||mine is a 2013 with 3.21's and 265/75-16's and it is 1st/2nd consistently is 2500-2600 rpm under normal driving. If I really romp on it then it is much higher. I have a aev procal and have adjusted my speedo for tire size. under normal conditions it shifts just above the green on the tach.|
|01-01-2013 10:27 PM|
2012-'13 auto trans. rpm shift points
What's your rpm range (light-heavy accel.) for a 1st-2nd gear shift...? Please disclose if you're stock or running bigger tires, gears, etc... Thank you, guys!
I just think this tranny is unpredictable at times...