Tranny mods?

Redog · 12-22-2003, 12:48 AM

I know that we have a 4t45 tranny in our Aleros but has anybody put a 4t40 tranny or a regeared tranny in their cars? If so, how much?

12-22-2003, 07:17 AM

Ok, the 4T40E and 4T45E are the same transmissions, with the following exceptions

V-6 4T45E wide Chain and 5 plate clutch set up for direct (3rd) 3.05 final Drive

I-4 2.4L skinny Chain and 5 plate direct clutch, overal final drive 3.43 final drive

I-4 2.2L Eco-Tech skinny Chain 4 plate direct clutch. 3.91 overrall final drive.

Also torque converters are different.

So swapping to a 4T40E would be bad with the v-6, you could rip the chain up, and depending also wrip up direct clutch.

Also any change in gear ratios, will force a recal of the PCM and since GM doesn't supply custom cals, that kinda hoses you that way.

The only differences

12-23-2003, 09:51 AM

Why would you want to do that anyway?

Redog · 12-23-2003, 05:18 PM

Just thinking that if I ever blow up the tranny from too much power or racing on the track taht I would get it regeared. If it's going to cost $1500, I'd put out like an extra $500 to save money in the long run.

Plus how fast you are is in the tranny. I like to take my car to the track

12-24-2003, 10:40 AM

Ok. Well, you'd need some heavy mods to blow your tranny, but it could happen. Why not just upgrade it before that happens? There are kits out there.

springs fastest alero · 12-25-2003, 07:49 PM

well no real mods yet but its a work in progress.
dont be too surprized if you see a few manual tranny V6's running arround soon

jturkey69 · 12-28-2003, 07:10 PM

ok john...so what tranny??..get a rag?,,,and also you swapped to a ga/gt...did you have any issues with re-calibrating the speedo??

springs fastest alero · 12-28-2003, 07:46 PM

Quote:

Originally posted by jturkey69@Dec 28 2003, 05:10 PM
ok john...so what tranny??..get a rag?,,,and also you swapped to a ga/gt...did you have any issues with re-calibrating the speedo??

my car came with the gagt tranny
it was special ordered for the dealers son that way but the car came before the paper work was ready.
I'm looking at the getreg/muncie 282

jturkey69 · 12-28-2003, 09:26 PM

ok...i thought you swapped it in...so you arent sure if ill have issues when i put mine in then?...
as for the get/mun. 282...what kinda of avialable parts are there for those, and which bellhousing tdo you need to use?

12-29-2003, 06:20 PM

Hmmm...I thought it was the exact same tranny as ours other than the gearing was set different. Which, if that was the case, I would have thought you could of just swapped in a gt pcm at the same time you switched the tranny. That seems way too easy so Im sure there is alot more to it.

jturkey69 · 12-29-2003, 07:20 PM

^^i have no idea...i have the ga/gt tranny in my garage, just waiting for a few more things to come in before i put it all together...i expect the car to be done around march for sure. so until then...i guess its just speculation

springs fastest alero · 12-29-2003, 08:00 PM

Quote:

Originally posted by jturkey69@Dec 28 2003, 07:26 PM
ok...i thought you swapped it in...so you arent sure if ill have issues when i put mine in then?...
as for the get/mun. 282...what kinda of avialable parts are there for those, and which bellhousing tdo you need to use?

as far as I know its just a different reluctor wheel in the tranny
but the cal is the same so you should be able to put in the tranny and everything will be fine.
they wouldnt of done it to my car if it required extra work than just bolting in the different tranny

12-29-2003, 10:23 PM

Ok, it's not a different reluctor wheel. It is the same the difference is that the Alero v-6 get's a 3.05 final drive the GA/GT get's a 3.29 final drive. So yes that means you are going to need the GA/GT calibration. Other wise shift pattern is going to be all fubar, and shift pressures are going to not behave the way they are calibrated to.

So if you are going to do this mod in the hopes of increased durability, well, you aren't gaining anything there. The gain will be in the launch due to the higher final drive, that is if you can keep traction.

12-29-2003, 10:55 PM

So does that mean that one could just swap pcms from the gt to the alero and have the gt gearing? Or just swap in a properly calibrated dhp pcm for the same year gt?

12-29-2003, 11:01 PM

I have not clue on the after markets? are those complete PCM's or just add ons to the stock PCM's Also I don't know if you could just swap the PCM in for the GT. The SE v-6 and a gt are different trans cals, but I am not sure on the engine calibration. I don't see why there would be a difference. I mean same engine, same air box exaust and all, so it should be a direct PCM swap. You will probably have to do a key learn though if you swap factory PCM's.

01-06-2004, 07:46 PM

Well in all that one of the best things u can do is GET A TRANNY cooler...

Cooler temp on the trans means longer life...

I got one and when its warmer out i will install it.

springs fastest alero · 01-07-2004, 03:10 AM

Quote:

Originally posted by overdrive75@Dec 29 2003, 08:23 PM
Ok, it's not a different reluctor wheel. It is the same the difference is that the Alero v-6 get's a 3.05 final drive the GA/GT get's a 3.29 final drive. So yes that means you are going to need the GA/GT calibration. Other wise shift pattern is going to be all fubar, and shift pressures are going to not behave the way they are calibrated to.

So if you are going to do this mod in the hopes of increased durability, well, you aren't gaining anything there. The gain will be in the launch due to the higher final drive, that is if you can keep traction.

actually you can go withing a certan percent without messing up the computer
but too far out of spec and it won't adjust
my friends played with this.
they tried gears from a 2.4L auto but it was too far out of spec.
3.07 and the 3.29 would interchange without causeing a problem

01-07-2004, 07:16 AM

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.

01-07-2004, 07:48 AM

Quote:

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.

What does that calculation? The PCM?

If the calculation was coming from the pcm...and the transmisions between were the exact same except for the final drive, why couldnt you just swap the chip from the gt at the same time?

01-07-2004, 01:29 PM

Quote:

Originally posted by Alerosince99@Jan 7 2004, 08:48 AM

Quote:

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.

What does that calculation? The PCM?

If the calculation was coming from the pcm...and the transmisions between were the exact same except for the final drive, why couldnt you just swap the chip from the gt at the same time?

That's correct a PCM from a GT must go with a GT trans. The PCM for the base v-6 goes with that one.

And yes the PCM calculates the gear ratio.