I was looking into what other cars have our same trans and I saw the g6 has the same auto trans. I noticed the gear ratio on the g6 is higher than my car. I am thinking if it would be fine if I swaped the gears of a g6's trans into mine. Would it work? I seen swaps on trucks amd rear wheels drive cars but idk about front wheel drive since the gears are in the tranny and not the differential.

 

it is possible however not easy. the final drive ratio in the transaxle is a combination between the ratio off the differential and the chain sprockets. changing this ratio requires partial or complete disassemblely of the transaxle. on top of that being electronicly controlled the pcm will require reprogramming/tuning for the new gear ratios. without tuning you could end up with poor quality shifts, slipping, harsh shifts, gear ratio error codes, and failsafe transmission operation.

unless your building the transmission, its generally not worth it.

 

I see. Thanks for the info. I am planning on building this trans if I can find the available parts. Do you know where I may find them?

 

Contact ZZP and see if they can sell you some since they sell a built auto trans. I'd think they'd sell the parts if they're still making a profit.

 

best thing would be to find out exactly what differential parts you need (there are 3 parts that determine the gear ratio in the diff, the diff itself, the sungear and the ring gear) and what combo of sprockets you need. once you know that, head to a local transmission shop. often times transmission shops have transmission cores around, or parts from a disassembled core.

 

I took the info you gave me and looked into different things. I found that they sell parts for.the 4T45e. But idk if it will work on my 09 since most people that buy them have grand ams and others. But zzp uses the same brand clutches on their built trans. But idk if they are the same ones.

 

If it were me I would buy the different geared trans and build that...then if you have HPT get a stock file for a G6 and compare the trans differences and copy it over.

 

You are right. That actually sounds like a better idea. I will update what I end up doing or if I find more info.

 

if your going to get another transmission to build, make sure its from an ecotec and the same year. there have been several changes in the 4t40e and 4t45e over the years and some will have different sensors (mainly the mlps, they have both internal and external designs and arent interchangable). a g6 or malibu with a 2.2 or 2.4 would be your best bet. im not sure of the ratios they have, but a large car with small engine should have a numerically higher gear ratio than a cobalt/g5. might also want to look at an hhr.

 

Yea I was wondering about sensors and things like that and I guess ill have to look for a 4T45e of an 09 G6 with the 2.4

Do you think the sensors should be the same with my 09?

 

should be. the transmissions will be basicly the same aside from gearing. around 2006 or 2007 gm change the 4t45e from an external mlps to an internal one. as long as you get one that doesnt have the mlps on the outside of the case you should be ok.

 

Alright got ya. Im putting the trans stuff on pause at least untill I get my turbo kit in. Planning on doing the turbo and then rods, pistons, rings etc. And then move to the trans. Gonna be looking into the trans stuff when buying pistons and all to get it on at the same time.

For now im going to keep reading build threads

 

I've never looked into gear ratios and all that so I don't know anything about them but what would a higher ratio do? Shorter gears? I was wondering what to do with the trans because at the power level i plan to be at it wont hold. Was just going to get a built one. My thought is since right now 3rd gear seems like a pos and is looong as heck and makes the car feel like it loses power in it, then I would just install cams. Cams would shift the powerband and make the longness of the gear be beneficial instead of having to deal with powerloss.

So...basically...if what nhanson suggested works and those have a little bit longer gears then I'll be up for this too haha

 

Well a higher gear ratio means shorter gears. They are good for drag racing since thats the only kind of track we have around the area haha. I plan on turboing my car so shorter gears would help me do a faster 60ft time therefore a faster 1/4 time. It would give the car more torque imo lol thats what I've seen and felt in different cars and trucks my brother has done it in lol

 

I actually dont mind 3rd gear now that Ive had some actual power through it. 4th gear is junk for sure though.

Plus I havent tested out shifting over 7k yet

 

Idk just feels like the gears are too long...lol.

Can you talk to tony and ask him if he can get me pricing on some stuff? Not just feeling around actually gonna be building soon lol