Transmission question.

[jabartram]

search didnt help. how do i find out exactly which transmission i have? i'm looking to buy a second tranny to have rebuilt with all the good stuff and i want to be sure to get the correct one.

[lord2heart]

http://sites.google.com/site/aleromo...e/transmission

[jabartram]

thank you for the link, but i need to know which exact model is sitting in my car.

Assuming it's the stock transission that came in the car and you have a V6, you have a GM Hydramatic 4T45-E transaxle with a 3.05 final drive ratio.

[jabartram]

so getting one out of a same year grand am will be ok, except the final drive ratio correct?

[Redog]

If you get it out of a GA, get it out of a SE and not a GT, unless you have HP Tuners to reprogram the PCM

BTW, what "good stuff" are you talking about? I would like to know this info for my tranny

[BlackJack]

He's got the PowrTuner, so that won't be a problem for him.

Hey James, if you want a little bit more low-end torque, get one from a GAGT (2003+) since it's a 3.29 gear ratio. The GASE has the same 3.05 ratio we have in the Alero. Just make sure you extract the transmission settings from a GT .bin file if you do.

[Runaboveit]

Originally Posted by BlackJack

The GASE has the same 3.05 ratio we have in the Alero.

That site linked says the base GASE V6 does not have a 3.05, but rather 3:63.

I don't know either way, but thought that should be pointed out and information updated if necessary.

[jabartram]

Originally Posted by Redog

If you get it out of a GA, get it out of a SE and not a GT, unless you have HP Tuners to reprogram the PCM

BTW, what "good stuff" are you talking about? I would like to know this info for my tranny

i'm still trying to talk to gectek, when i finally do i'll let you know. i did get my quote from Ben on my new engine parts.

[BlackJack]

Originally Posted by Runaboveit

That site linked says the base GASE V6 does not have a 3.05, but rather 3:63.

I don't know either way, but thought that should be pointed out and information updated if necessary.

No, it says the GA "base model", not GASE - has a 3.63 but notice all the other GM vehicles listed in that category are all the 4-bangers. Had to have that low end pull in that ratio for the smaller engines to get that heavy car moving. I'd be willing to guess that the 3.63 gear ratios were also in the 4t40 rather than the 4t45.

Most of the "mid-model" V6 cars had the 3.05, and the GT or sport editions had the 3.29

There are several trim model cars missing from that list.

[Runaboveit]

Ah, I always thought the SE was the base model.

Thanks for explaining.

[BlackJack]

bah, it could be, but GM normally runs and "unlabeled" model as their base, and an SE, LE, SLE or GT trims for other models above base.

You might be right on that one, I'm completely brain fried right now from taking online courses.


*edit - confirmed.

Grand Am came in five different trims: SE, SE1, SE2, GT and GT1. Base powerplant for the SE and SE1 remained a 2.4L Twin Cam mated to a 4-speed automatic only. The SE2, GT and GT1 sported a new 3.4L 3400 V6 engine.

1999-2005: 4-speed automatic with overdrive (4t40e for SE Models, 4t45e for GT models)

[kwhauck]

Interesting, blackjack what is your opinion on high FDR?

when you look at the gtp's some people would step down to a 2.93 to get a good launch and quarter, but at the same time some people step up to a 3.69 or even higher,

I hear some of the j-body guys complain about the 3.94 like I have saying that first is too steep, but there are cobalts that get out of the hole fine and they have something rediculous like 4.09...

[BlackJack]

You can't really "step down to" a 2.93 with the GTP, since that's what actually comes factory in one. That's what I'm running in the Alero right now.

my personal opinion is if you have rediculous amounts of torque from the dig, you're going to break shit (like axles, I/O shafts, diff's etc).

I personally like to be able to produce torque through as much of the powerband as possible, and I think the "way too small" gear ratio's dont really help all that much. Yeah, they're great for the dig (if you got traction, and a bulletproof setup) but they're horrible for being able to run-out your gears. Kinda like nutting too fast.

That's why if I have the '65 built, I'm currently planning to stay with the 2.93, and just up the stall speed to a 3k with lockup, considering I'm also using it for a daily driver and highway car. The 3k stall speed will get me off the line with that huge turbo, and I need the huge turbo so it doesn't fall on it's face from mid-range to the end of the powerband.

Gear ratio is really just a matter of what suits you, your car's powerband, and where you need the torque. I'd go with a tighter gear if I had a N/A setup and was mostly track or in-town driving. But for a midrange to top-end monster, I'm keeping on my current end of the scale.

Consider that back in '08, I made a 14.5 run on 5 cylinders and a tune that wasn't dialed in for the altitude. Where I ran the other guy down was after the 100ft mark, and then I left him exponentially. I had so much lag off the line from the loss of that one piston (5 cyl's trying to spool a huge turbo) that I could have easily made up 2 seconds time in the first half of the track with all 6 pumping, and a higher stall to be in boost on launch.

[kwhauck]

good points, I may just keep the 3.94 gearset for now being N/A and then once I figure out the custom intake manifold and actually get the boost going again, i'll change out the gearset....

on the upside, I found this website the other day, pretty badass IMO, download their free CAD software, you do the designing (and save butt-loads of money), and then they churn out the part for you, They even have a one click quote for machining prices built into the program

http://www.emachineshop.com/

[BlackJack]

um....I think we kinda raped Jame's thread. Ok, back to the task at hand. There should be a metal "tag" riveted to the passenger side shaft housing on the transmission that should tell you a code like MN5 or something to that effect. I dont know if that code will tell you the specific gear ratio or not, but I know it will identify the family of transmissions, such as '40, '45, '65 etc.

[kwhauck]

oh yeah sorry james.....lol......maybe cliff can chime in on the metal tags, he usually knows this stuff......

[jabartram]

If the discussion helps people learn, its all good.

[kwhauck]

I was thinking last night and I believe in an autocrossing, that the 3.63 would be the most beneficial to you, it will help you stay in your power range more......

[jabartram]

if anybody could help me out, i'm changing my tranny cooler setup and i need to know if the top line coming out of the tranny is going to the top of the radiator? the line circled in red.