I think I have an Idea, tonight when we die down at work I'll try and post the info your looking at.

GO GM GUYS!

 

Does anyone have a fax machine? I printed it out and I can fax it to you if you'd like.

This is driving me nuts! I wish to God I could link you guys to it! AGGGGHHHHH!

Anyone with a fax machine let me know and it will be on the way.

 

Fax machine anyone at all?

 

Hey half cent. Did you take your tranny to a shop to have that installed. Also which one did u get? The stree or race version. What can be done with hp tuners TCM?

 

Well I faxed my stuff to half cent so when he gets around to it he'll be able to confirm that there are indeed 2 different automatic transmission gear ratios for the Cobalt. A 3.63 and a 3.91 final drive.

 

IPT built my trans. They had to remove my differential and send it to Engineered Performance to have it modified. I got the street version.

Here is the parts listing the Jackalope was talking about:

It would appear that there are in fact two different final drive ratios between the LS and SS. I have always been aware that the 4T45E had different ratios available, but before now had always thought that only one ratio was in all the Cobalts. This information is NO WHERE else that I have looked in the past year. In fact, I thought I had settled this issue, so I guess I have not.

Question: My data was from the 2006 model year. This is from the 2007 models. Could there have been a switch in the new model year?

There ya go boys. However, the fact still stands. If you want a different final drive ratio for your 4T45E, all you have to do is swap out the differential, not the whole trans.

 

Yeah, I noticed that, too. It says years "07-07", where as the websites, USA and Canada, likely still have '06 model year stats in them. Perhaps the '07 2.4 will have a little more pick-up than an '06?

I suppose if you want even more, you could find a way to put the 2.0's 4.05 on there. Don't think that job would be quite as easy, though.

 

Just looked and the 06's show the exact same page just with the 06-06 thing instead of 07-07.

And since th SS/NA wasn't around in 05 it looks like it just the 2 years so far.

Halfcent, thanks bro you really came thru on this one! Its frustrating not being able to show you guys what I can see here at work. Thank you.

 

Is the differential contained within the tranny, how difficult is it to change?

 

Yes and it looks like a pain in the ass!

 

06 autos had different transmissions for different trims. Both have an MN5 RPO but the two submodel codes for each are:

EHJ - used in the L61
ELJ - used in the LE5

 

I got the MN5 code but the subcodes I'm showing for 06 are FX2 for the 3.91's and FY1 for the 3.63.

That EHJ and ELJ show like they may be stamped on the case or on an ID tag on the tranny itself. So this may be a way to tell if you find one out of the car. Way to go looking out Witt! You may have figured out that they are tagged different on the outside! No I'm not being a smart ass I'm being serious cause some junkyards will pull the parts and have them out of the cars at least NOW they'll be ab;e to tell what gears it has without opening it up! SCORE!

 

I have a breakdown on whats on the tag, give me a minute I'll see if any of that is listed.

 

I dont "think" the model of the transmission is gonna be listed on the tag, just a part number. It does say "model" as one spec listed, but I think that has to do with the car its being used in, rather than transmission model itself. However the original part number (24213734 for example) is listed right underneath the word "Canada". Thats the only thing I can say for certain.

 

DAMN! I thought we had it all figured out!

DAMN YOU GM! DAMN YOU TO HELL!! (insert image of Charton Heston from Planet of the Apes)

 

I never got around to getting the exact copy off the website. I got swampped at work tonight. But Like it was said before, there are definetly 2 different final drive ratios.

 

It gets better -- I've been researching this issue for awhile. The Chevy website and all the literature on the Cobalt only lists the 3.63 ratio in the SS 2.4. But thanks to a friend that can log into the GM site to decipher the VIN codes we have found that the SS 2.4 does have the 3.91 gears. The MXN tranny build code is the 3.91 geared 4T45e version. All the SS 2.4 VINs we have deciphered have the 3.91 yet the window sticker does not show it.

Interesting....? Although the planetary gear set will go right into the 2.2L MXO tranny I'm still not convinced you could do a computer adjustment to correct shift points and such. This is where we need a Chevy vehicle computer Guru! Any out there that would help us out?

 

I know what the chevy site lists, though I never look at it. I just simply log myself onto GM's internal sites and get parts info and repair info and just about anything else I want. So I know all about the GM sites. And its not listed in the VIN Code its listed under the RPO codes.

As far as swapping gear sets all you would need to do is get the TCM to accept the calibration for the other tranny. However this isn't truely possible because the software program will not allow such to happen. And no you cannot just switch TCM's.

 

Do you know what a VSI is? (I don't) I was told if you put the gears in, the dealer could ask for a VSI(?) that would correct the computer to work with the lower gears.

 

No such thing as VSI, we do have VCI however but its not as simple as calling and requesting the confirmation to program the TCM. We have to state reason and give them the vin.

 

Obviously my memory isn't so good with three letters Can I ask you to call the particular office and ask if a VCI could be accomplished for the base Balt if one were to install a complete new 2.4 tranny in an LS/LT 2.2? If need be I'd have the dealer install it.

Thanks

 

Won't work, said it once and I'll say it again. The VCI does a VIN check and also takes the technicians number so if anything like this would happen the technician would be in trouble as would the dealer.

 

??? Is there a GM Transmission Swap Police Department?

What trouble would there be if you swap out a tranny for a customer and then request that the new gear ratio be input into the car's computer so it could be driven?

 

Despite the truth of all this talk, I would put forth that it isn't really necessary. I am running a custom high stall torque converter on the street everyday. It makes my engine rev slighty higher then a stock car otherwise would at lower speeds (once above 40 the RPMS mate back up). However, my trans still shifts through the gears normally. The slightly higher drive ratio would probably be transparent to the computer.

 

The speedometer would be off, computer would shift transmission too early thinking the engine was rev'ed out. In this case the gear change is nearly 7%. Converter doesn't affect this -- who made your converter?