View Full Version : gagt trans
well my trans is going. can i put a gagt trans in and drive it to Chicago area for a flash. also what are the advantages to a gagt trans
01GrandAm
08-11-2012, 10:16 PM
GAGT Trans has a 3.29 gear ratio.
If you install the trans with the improper PCM, it will not shift properly.
Your best bet would be to pick up a spare PCM and have it programmed for the 3.29 gearing.
xXManwhoreXx
08-11-2012, 10:29 PM
I have a gagt tranny and mine shifts fine.
Eric did u have to flash it to work
what's the advantage of the higher fdr
happyisthealero
08-11-2012, 11:43 PM
I think faster shift times? If so I'm looking for that gear ratio at a junkyard when I get the extra cash....
Off topic, but relates to the tranny. What might the gear ratio's be in a Montana's and Silhouette's?
Papa Rad17
08-12-2012, 12:47 AM
having your 3500 lower I shouldn't it being to huge of task. the gear ratio of the the trans is where the alero's loose a HUGE majority of their potential power. the better gearing would be good investment but...Bill? ecotec5, would have the be the one to tune it in since your pcm is flashed with his hptuners.
yea IM wondering if i get this trans if it will accelerate quicker. and if i can drive it to meet bill to get my pcm flashed
Shiwnath
08-12-2012, 01:42 AM
The GAGT tranny is shorter geared so you'll see improved performance in acceleration BUT with shorter gears you'll be cruising at a higher RPM and it'll most likely use more fuel while on highways and what not.
AleroB888
08-12-2012, 03:10 AM
yea IM wondering if i get this trans if it will accelerate quicker. and if i can drive it to meet bill to get my pcm flashed
Probably, but you have to make sure the year and model match up, see this thread:
http://www.aleromod.com/forums/showthread.php?t=34805&highlight=transmission+GrandAM
so i gotta get one out of a 01?
sleepyalero
08-12-2012, 01:46 PM
no, the pcm and tranny need to match, you could put an 04 in it with an 04 pcm,
but a 03 tranny and 04 pcm wont work.
oh i gotta grab the pcm aswell? will the car run with a difference pcm
01GrandAm
08-12-2012, 07:28 PM
I will be putting a 2004 GAGT trans in my 2000 GAGT.
I have already swapped out the pressure solenoid with one from a 2000 model year, so we will see what happens when I get the car running.
xXManwhoreXx
08-12-2012, 07:56 PM
I didnt do mine the.shop just put one in when I asked em too
Papa Rad17
08-13-2012, 04:46 AM
oh i gotta grab the pcm aswell? will the car run with a difference pcm
in your case you'd probably wont to get a model year trans. swapping the pcm would mean having to get a new license to re-tune wouldnt it?
Shiwnath
08-13-2012, 09:07 AM
The question now is how swappable are different model year PCMs? I know that they will definitely have different service numbers on them, but I don't know if that'll cause any sort of issue.
Redog
08-13-2012, 07:40 PM
I have an 01 PCM in my 2000, and I cannot change the VIN to the correct 2000 one. I get "Mismatched OS pair" error message with my HPTuners.
All the gears are the same in the GAGT and Alero transmission. The only difference is the FDR being 3.29 instead of 3.05. However the PCM WILL trip a SVS and I'm not sure how well the car will run.
A higher numberical FDR is a smaller gear ratio, which will turn the drive wheels faster at the same RPM than the orginal FDR.
It's not exactly the same as a RWD car, but it's the same idea: My Delta has 2.73 gears in the rear end. I'm plaining on changing the gears to either a 3.42 (my fav) or 3.73. If I change it to a 3.73, the rear end gears will turn one full turn more than the 2.73.
With the current 307, at 70 MPH, my engine is turning at 1900 RPM's with a 27 inch tire and 2.73 rear end. With 3.42's and the same size tire, the engine will be turning about 2400 RPM at 70 MPH. However, it did shave .2 off my 60 foot with the 307 ;)
AleroB888
08-13-2012, 09:32 PM
The question now is how swappable are different model year PCMs? I know that they will definitely have different service numbers on them, but I don't know if that'll cause any sort of issue.
I don't know if it can be done in every case, but if you have the licensing for both models, you can overwrite one program completely over on the other PCM. For instance, I can write my 2003 Alero V6 file over any 1999 Alero V6 PCM, and use it in my 2003, because I am licensed for all 1999 Alero V6, and my particular 2003 V6.
A professional tuner may be able to write over any PCM, like a Malibu, with your Alero program. At least that was the case for the ""all GM" HP Tuners program I borrowed from Mike (scalero) years ago. But sometimes he had to make specific requests to HP Tuners for unsupported models.
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