Aging auto trans
07-30-2011, 10:25 PM
#1
Aging auto trans
My 06 LS has about 73K miles on it. I am planning on getting a tune in the month of August from Vince at Trifecta. I will just have bolt-ons so nothing fun haha. I am wondering if there is anything that I should do or tell him? I was planning on just asking for "what ever is normal for an auto". On the ordering page for additional requests I assume most people check off: Torque Mgmt Delete (Auto Trans) and Increase shift firmness.
Since I do have a few miles on the cobalt and plan on putting many more on, does anyone think I will run into issues trans related after the tune? I drive kinda hard as it is and will probably continue doing so for many more miles. Does anyone forsee issues? Maybe I'm just being paranoid? ..lol
I always thought I would want to install a trans cooler but I thought I read in some thread that they would not work or would not be worth the hassle. Has anyone actually installed a cooler and liked it or hated it or able to show that it made a difference?
I do not want to purchase a performance transmission. I would prefer to always leave the trans alone if possible.. I'm assuming its run by magic and rainbows so if parts had to be upgraded or rebuilt I'd need to take it somewhere.
Since I do have a few miles on the cobalt and plan on putting many more on, does anyone think I will run into issues trans related after the tune? I drive kinda hard as it is and will probably continue doing so for many more miles. Does anyone forsee issues? Maybe I'm just being paranoid? ..lol
I always thought I would want to install a trans cooler but I thought I read in some thread that they would not work or would not be worth the hassle. Has anyone actually installed a cooler and liked it or hated it or able to show that it made a difference?
I do not want to purchase a performance transmission. I would prefer to always leave the trans alone if possible.. I'm assuming its run by magic and rainbows so if parts had to be upgraded or rebuilt I'd need to take it somewhere.
07-30-2011, 10:43 PM
#2
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if your real worried dont have him boost the pressure in the trans, but im sure you will be fine. im about to get a trifecta tune and im gonna have him go all out (im at 42k)
07-30-2011, 10:48 PM
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im trifecta tuned as well and the gov. is deleted and firmer and quicker shift points. a tranny cooler is cheap and should be easy to install and most ppl would recommend it to some1 with more miles im sure. but i dont have one and i drive kinna hard as it is also. i have 53k
07-31-2011, 02:03 AM
#10
im trifecta tuned as well and the gov. is deleted and firmer and quicker shift points. a tranny cooler is cheap and should be easy to install and most ppl would recommend it to some1 with more miles im sure. but i dont have one and i drive kinna hard as it is also. i have 53k
08-01-2011, 02:21 AM
#15
the 4t45e is a very good tranny, id say one of gm's best transmissions in the past 2 decades. they have been in a lot of cars and in 8 years in the transmission industry ive only seen a handful of failures, aside from broken cases (seems to be a common thing). in the later years they do seem to have one inherent flaw, and thats the feed pipes in the pan (specifically the forward clutch feed pipe) breaks off its mounting plate. this issue can cause flares and slips before causing no forward enagagements. its an easy fix, drop the pan and unbolt the pipes and bolt new ones on.
soft shifts are actual slipping, causing heat and wear. the shock of hard shifts can cause broken geartrain, damaged teeth on clutches, and exessive strain on the pump. the key is a balance. with simple bolt ons, id leave the tranny tune alone, or just increase the epc pressure a slight bit to give a little more positive feel. if you plan on going forced induction you will need to up the epc pressure to keep the tranny from burning up.
all gm transmissions have adaptive shift strategies. what happens is the pcm measures the amount of time it takes from the time it commands the shift solenoid to change state (turn on or off) to the time it sees the correct gear ratio based on info from the input and output speed sensors. the pcm will then adjust epc pressure during the shift to meet the target shift time. if looking at a scan tool (im sure hp tuners can get the info to) you will find a list with different cell numbers, and the value in each. the value indicates how many percent the line epc pressure is being increased or decreased for each cell (negative numbers mean the shift is happening too quick and its taking pressure away). now what happens is as the tranny wears the numbers get higher till the computer can no longer compensate, and at that point it will set code p1811, max adapt and long shift, and the tranny will need to be overhauled to correct the code.
what does that all mean as far as tuning? you can keep an eye on these values as you tune for more power and adjust the epc programmed values to keep the shift adapt numbers as close to 0 as possible. it works similar to long term fuel trims.
soft shifts are actual slipping, causing heat and wear. the shock of hard shifts can cause broken geartrain, damaged teeth on clutches, and exessive strain on the pump. the key is a balance. with simple bolt ons, id leave the tranny tune alone, or just increase the epc pressure a slight bit to give a little more positive feel. if you plan on going forced induction you will need to up the epc pressure to keep the tranny from burning up.
all gm transmissions have adaptive shift strategies. what happens is the pcm measures the amount of time it takes from the time it commands the shift solenoid to change state (turn on or off) to the time it sees the correct gear ratio based on info from the input and output speed sensors. the pcm will then adjust epc pressure during the shift to meet the target shift time. if looking at a scan tool (im sure hp tuners can get the info to) you will find a list with different cell numbers, and the value in each. the value indicates how many percent the line epc pressure is being increased or decreased for each cell (negative numbers mean the shift is happening too quick and its taking pressure away). now what happens is as the tranny wears the numbers get higher till the computer can no longer compensate, and at that point it will set code p1811, max adapt and long shift, and the tranny will need to be overhauled to correct the code.
what does that all mean as far as tuning? you can keep an eye on these values as you tune for more power and adjust the epc programmed values to keep the shift adapt numbers as close to 0 as possible. it works similar to long term fuel trims.
08-01-2011, 03:16 AM
#17
the 4t45e is a very good tranny, id say one of gm's best transmissions in the past 2 decades. they have been in a lot of cars and in 8 years in the transmission industry ive only seen a handful of failures, aside from broken cases (seems to be a common thing). in the later years they do seem to have one inherent flaw, and thats the feed pipes in the pan (specifically the forward clutch feed pipe) breaks off its mounting plate. this issue can cause flares and slips before causing no forward enagagements. its an easy fix, drop the pan and unbolt the pipes and bolt new ones on.
soft shifts are actual slipping, causing heat and wear. the shock of hard shifts can cause broken geartrain, damaged teeth on clutches, and exessive strain on the pump. the key is a balance. with simple bolt ons, id leave the tranny tune alone, or just increase the epc pressure a slight bit to give a little more positive feel. if you plan on going forced induction you will need to up the epc pressure to keep the tranny from burning up.
all gm transmissions have adaptive shift strategies. what happens is the pcm measures the amount of time it takes from the time it commands the shift solenoid to change state (turn on or off) to the time it sees the correct gear ratio based on info from the input and output speed sensors. the pcm will then adjust epc pressure during the shift to meet the target shift time. if looking at a scan tool (im sure hp tuners can get the info to) you will find a list with different cell numbers, and the value in each. the value indicates how many percent the line epc pressure is being increased or decreased for each cell (negative numbers mean the shift is happening too quick and its taking pressure away). now what happens is as the tranny wears the numbers get higher till the computer can no longer compensate, and at that point it will set code p1811, max adapt and long shift, and the tranny will need to be overhauled to correct the code.
what does that all mean as far as tuning? you can keep an eye on these values as you tune for more power and adjust the epc programmed values to keep the shift adapt numbers as close to 0 as possible. it works similar to long term fuel trims.
soft shifts are actual slipping, causing heat and wear. the shock of hard shifts can cause broken geartrain, damaged teeth on clutches, and exessive strain on the pump. the key is a balance. with simple bolt ons, id leave the tranny tune alone, or just increase the epc pressure a slight bit to give a little more positive feel. if you plan on going forced induction you will need to up the epc pressure to keep the tranny from burning up.
all gm transmissions have adaptive shift strategies. what happens is the pcm measures the amount of time it takes from the time it commands the shift solenoid to change state (turn on or off) to the time it sees the correct gear ratio based on info from the input and output speed sensors. the pcm will then adjust epc pressure during the shift to meet the target shift time. if looking at a scan tool (im sure hp tuners can get the info to) you will find a list with different cell numbers, and the value in each. the value indicates how many percent the line epc pressure is being increased or decreased for each cell (negative numbers mean the shift is happening too quick and its taking pressure away). now what happens is as the tranny wears the numbers get higher till the computer can no longer compensate, and at that point it will set code p1811, max adapt and long shift, and the tranny will need to be overhauled to correct the code.
what does that all mean as far as tuning? you can keep an eye on these values as you tune for more power and adjust the epc programmed values to keep the shift adapt numbers as close to 0 as possible. it works similar to long term fuel trims.
08-01-2011, 01:06 PM
#18
i would recommend a tranny cooler for anyone with an auto that drives hard. for every 10*f the fluid temp goes up you cut the fluid life in half. that being said, the tranny does need to get up to proper operating temps (generally around the same as engine temp, around 180-195*f) for it to work optimally. i always recommend a self ragulating, or stacked plate cooler. these coolers have orifice plates in them, this allows fluid to only flow through the bottom part of the cooler when the fluid is cold, and as the fluid heats up its able to go through the smaller orifices and use more of the cooler. also, run a tranny cooler in series (unless replacing a badly damaged tranny, then run the cooler on its own) running through the rad first and then the cooler. and never use a tube and fin cooler on a modern transmission. for one, they arent very efficient and 2 they dont allow the tranny to get to operating temps, its like running your motor with no thermostat.
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