Tranny mods?

Ahh I get you now.

The pcm controls final gear ratio but there is something hardcoded in the trans itself that needs to match up.

Is there anyway to change that hardcoding in the trans?

Originally posted by Alerosince99@Jan 7 2004, 04:07 PM
Ahh I get you now.

The pcm controls final gear ratio but there is something hardcoded in the trans itself that needs to match up.

Is there anyway to change that hardcoding in the trans?

Ok all 4T40E's and 4T45E's have the same first, second, third and forth gear ratios. The final drives can change and the Torque Converter depending on application.

The 3400 alero has a 3.05 final drive. The 3400 GAGT has a 3.29 final drive.

Those final drives are calibrated.

Ok, so the transmission needs to match the calibration in the PCM.

That said.

The PCM must follow the transmission.

As far as changing transmission calibration, that requires a calibration flash.

If you are looking to get a 3.29 final drive your best bet is to get the complete GAGT transmission, and the PCM for the GAGT.

[springs fastest alero]

Originally posted by overdrive75@Jan 7 2004, 05:16 AM
I calibrate this transmission for a living. It is not as simple as you guys think.

The transmission does not adapt shift lines. Only pressures, and even then it's gonna be all messed up because the transmission will never calculate that it is in the correct gear. Yes it does calculate ratio to verify it has made the gear change, and since it has a different final drive, it will never calculate the correct ratio, as the final drive is taken into account in the calibration.

Sorry to break it to you but you are wrong.

Well can't argue with facts
fact is nothing shows up in my car's vin proving it is a 3.29 fdr
but the dealer had proof of it and my car shifts the same as gagt's and sooner than aleros.
I also ran it through a program based on tire size max gear speed and stuff like that, that showed it as a 3.29 as well
from what we have found nothing was done to the computer yet my speedo and everything works correctly
I was told by a friend who talked to the guy that headed up the SC/T project that the computer is able to adjust for a very small ratio change and still be in spec.
like 15-17%% or less.
3.29 is only a 6% change from the 3.07 (factory alero gears)
My car works just fine and has 3.29 gears.
and it doesnt have a gagt cvomputer or the speed limiter would be 128

If I'm wrong why does my car work without a dimes trouble?
now changing to like 3.60 fubars everything
one of my friends tried that.

Originally posted by springs fastest alero+Jan 7 2004, 09:58 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (springs fastest alero @ Jan 7 2004, 09:58 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-overdrive75@Jan 7 2004, 05:16 AM
I calibrate this transmission for a living.Â;-) It is not as simple as you guys think.

The transmission does not adapt shift lines. Only pressures, and even then it's gonna be all messed up because the transmission will never calculate that it is in the correct gear.Â;-) Yes it does calculate ratio to verify it has made the gear change, and since it has a different final drive, it will never calculate the correct ratio, as the final drive is taken into account in the calibration.

Sorry to break it to you but you are wrong.

Well can't argue with facts
fact is nothing shows up in my car's vin proving it is a 3.29 fdr
but the dealer had proof of it and my car shifts the same as gagt's and sooner than aleros.
I also ran it through a program based on tire size max gear speed and stuff like that, that showed it as a 3.29 as well
nothing was done to the computer yet my speedo and everything works correctly
I was told by a friend who talked to the guy that headed up the SC/T project that the computer is able to adjust for a very small ratio change and still be in spec.
like 15-17%% or less.
3.29 is only a 6% change from the 3.07 (factory alero gears)
My car works just fine and has 3.29 gears.
and it doesnt have a gagt cvomputer or the speed limiter would be 128

If I'm wrong why does my car work without a dimes trouble?
now changing to like 3.60 fubars everything
one of my friends tried that. [/b][/quote]
I am not here to argue your facts. I don't know who your contact is, but that is not a correct statement. I have also never heard of the 3.07 final drive. It is not one the possible ones, so that fact is wrong.

As far as the 3.05 vs 3.29 arguement. Hey if you are running that without any problems, there is something that is different, and it will be the PCM.

As far as telling people to just swap their transmissions, will you put it in writing you will replace there trans when it fails, due to incorrect final drive for the given calibration.

[Naich]

Guys, I have been contacted by a GM worker who knows the ins and outs of the transmissions for our cars, and he wanted me to post this on here to clear up any confusion, and so someone doesn't go screw up their trans. for those people that are interested in haveing the 3.29 final drive in there alero's then need to have a PCM that is set up for the GAGT. If you do not have the correct calibration to run the 3.29 FD transmission, you are going to fail your transmission. The calibrations between the 3.05 FD and 3.29 FD are different in that shift pattern is not going to function as it should. Shift feel will be drastically impacted. With the impact on shift feel, there will be more clutch slip and eventually transmission failure. With the impact on shift feel, there will be more clutch slip and eventually transmission failure

[springs fastest alero]

you are the first to say its a 3.05
and how does my car work and have the alero speed limiter with a 3.29 fdr?
if it was a gagt computer my car would have a 128 speed limiter

Originally posted by springs fastest alero@Jan 7 2004, 11:18 PM
you are the first to say its a 3.05
and how does my car work and have the alero speed limiter with a 3.29 fdr?
if it was a gagt computer my car would have a 128 speed limiter

Ok, you need to pick up the Hyda-matic 4T40E technicians guide. That lists all the relevant information for 4T40 / 45 E transmission. It also lists the available final drive ratios. One of which is the 3.05 and you will find that the 3.07 is not listed as one.

I don't know how your car is cobled together, but I am serously doubting you have the 3.29 FD transmission. I mean who is this supposed paperwork from the dealer?

Springs, is it possible that the dealer had the stock alero PCM recalibrated to the 3.29FD? That would explain both the speed limiter, and why your car runs OK.

[Redog]

Originally posted by Big Poppa Naich@Jan 7 2004, 10:06 PM
Guys, I have been contacted by a GM worker who knows the ins and outs of the transmissions for our cars, and he wanted me to post this on here to clear up any confusion, and so someone doesn't go screw up their trans. for those people that are interested in haveing the 3.29 final drive in there alero's then need to have a PCM that is set up for the GAGT. If you do not have the correct calibration to run the 3.29 FD transmission, you are going to fail your transmission. The calibrations between the 3.05 FD and 3.29 FD are different in that shift pattern is not going to function as it should. Shift feel will be drastically impacted. With the impact on shift feel, there will be more clutch slip and eventually transmission failure. With the impact on shift feel, there will be more clutch slip and eventually transmission failure

What about the PCM on sale at PFYC.com for the GAGT?

Is it as easy as putting this in or does more have to be done?

Grand Am GT PCM

[Naich]

from my understanding, if you get the gagt transmission, you need a grand am gt PCM, be it tuned or not. You can't just get the PCM, you need both the 3.29 GAGT trans AND the PCM.

[jturkey69]

ok...here is a question then.....overdrive75..
for the ase pcm...most ppl were told to order the gagt pcm tune.....so if im ASSUMING right...when ppl did get the asse..then they should have also got the gagt trans?? i mean it does make sense that some aleros with the ase tune, arent all that faster, so if they ordered the gagt tune, then they could be havin more iisues then ??...does this make sense to you??

i just remember that when ppl said there was no ase for the alero, they wer told to ask for the gagt tune

if that is true...then the ase would actually be a good route to go with the gagt tranny installed.

please help us out here...i dont want to install the gagt trans i have and mess everything up in the process

[Redog]

Originally posted by Big Poppa Naich@Jan 9 2004, 12:37 AM
from my understanding, if you get the gagt transmission, you need a grand am gt PCM, be it tuned or not. You can't just get the PCM, you need both the 3.29 GAGT trans AND the PCM.

Yeah that's what I thought

Originally posted by jturkey69@Jan 9 2004, 09:28 AM
ok...here is a question then.....overdrive75..
for the ase pcm...most ppl were told to order the gagt pcm tune.....so if im ASSUMING right...when ppl did get the asse..then they should have also got the gagt trans?? i mean it does make sense that some aleros with the ase tune, arent all that faster, so if they ordered the gagt tune, then they could be havin more iisues then ??...does this make sense to you??

i just remember that when ppl said there was no ase for the alero, they wer told to ask for the gagt tune

if that is true...then the ase would actually be a good route to go with the gagt tranny installed.

please help us out here...i dont want to install the gagt trans i have and mess everything up in the process

That's correct, if you install your GAGT tranmission into your alero, you are going to need to have a PCM, weather it be a factory one or a tuned one that is set up for the GAGT.

To your other questions about people having more issues, then yes, this could be true. I am not sure what ASE's tune looks like or does to the stock one, but in this case, the underlying issues my not stand out, weather it be a Diagnostics code my not set, as with the factory PCM you would.

I am not familiar enough with what ASE does to trouble codes or doesn't do. If you are putting an ASE GAGT tune in an alero without the GAGT (3.29) trans, there are going to be some deffinate problems. Once again I do not know what ASE does in reguards to DTC's and stuff, so my best answer is those people that have done the ASE swap with a GAGT tune do have some issues and they may not stand out to them as problems.

[Naich]

but if there was a tune for the GASE, you would be ok, right?

Originally posted by Big Poppa Naich@Jan 9 2004, 02:34 PM
but if there was a tune for the GASE, you would be ok, right?

That's right a GASE tune will work fine in an alero with the alero trans.

[jturkey69]

thanx for the help...im gonna research some stuf about ASE and DHP. computer tunes before i start to mess with installing the gagt trans.

WHAT I WANNA KNOW IS WHY THE HELL OUR CARS TOP AT 107 AND THE GRAND AM GT TOPS AT LEAST AT 121. I HAVE AN 02 ALERO AND I AM AT 107 AND MY FRIEND JUST BOUGHT AN 02 GAGT AND HE GOT HIS TO 121....I AM PISSED!

Originally posted by 1WhiteOSV@Feb 27 2004, 01:25 PM
WHAT I WANNA KNOW IS WHY THE HELL OUR CARS TOP AT 107 AND THE GRAND AM GT TOPS AT LEAST AT 121. I HAVE AN 02 ALERO AND I AM AT 107 AND MY FRIEND JUST BOUGHT AN 02 GAGT AND HE GOT HIS TO 121....I AM PISSED!

Grand AM GT has tires that are rated to a higher speed than those that come on the alero and GM SE.

That's it pain and simple

It all boils down to tires.

^ Because that's where fuel cut-off is. Get new tires and a chip, and go as fast as you want.

Uhhh... stock Eagle RS-A's are v rated.... 149mph. Not so simple, now.