05 transmission in 02 truck?

jrfoust1

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I have a 2002 3500 4x4, can I use a 2005 3500 4x4 allison transmission on it? Will I need the TCM for the 05 to work?
 

2004LB7

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I'm pretty sure an 01 through 05 TCM should work.

Now are you looking at a manual transmission or automatic? because you put the thread in the manual one but then said you you have an Allison
 

jrfoust1

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I know the fuel injections system was redesigned but that's all I know about the lly I think the tranny is the same ,maybe upgraded to 6 spd but I don't know it the TCM was changed or the ECM inputs for it
 

1FastBrick

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I know the fuel injections system was redesigned but that's all I know about the lly I think the tranny is the same ,maybe upgraded to 6 spd but I don't know it the TCM was changed or the ECM inputs for it
6 speed was 06 and the TCM was different.
 

LBZ

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Cooler line fittings are different size/thread. You will need to swap bellhousings or get different cooler lines. The hose kits for replacing the cooler hard lines with hose often have fittings for both the ‘01-‘02 and ‘03-‘05 in them. Other than that no difference other than the ’05 has ( I think it’s the “G” solenoid ) in it. But yours won’t have the wiring for it in the harness so it won’t do anything.
 

1FastBrick

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Cooler line fittings are different size/thread. You will need to swap bellhousings or get different cooler lines. The hose kits for replacing the cooler hard lines with hose often have fittings for both the ‘01-‘02 and ‘03-‘05 in them. Other than that no difference other than the ’05 has ( I think it’s the “G” solenoid ) in it. But yours won’t have the wiring for it in the harness so it won’t do anything.
This is all Correct including the G solenoid.

I would just like to add along with the smaller cooler fittings in the bell housing, that if you try and put an early 01-02 trans into an 05 you will get a Phantom Code for that "G" solenoid but I am told it will still function correctly and you can disable the code with EFI live.
 

LBZ

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This is all Correct including the G solenoid.

I would just like to add along with the smaller cooler fittings in the bell housing, that if you try and put an early 01-02 trans into an 05 you will get a Phantom Code for that "G" solenoid but I am told it will still function correctly and you can disable the code with EFI live.
I thought you would only get a code if you added the wire for it that the 7’s didn’t have? It was my understanding that if you used your normal external harness it didn’t even know it was there and no code would come active.
 

darkness

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If I remember the ‘04 trans had the g solenoid and wasn’t used. Didn’t it have something to do with fluid flow while idling/off throttle sending fluid thru the cooler?
 

Bdsankey

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Conversion cooler line fittings or swap the bell housing
Likely swap your NSBU


The g-trim VB can remain, it would just be inactive. G trim sends additional fluid through the cooler at low rpm (essentially idle).
 
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1FastBrick

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I thought you would only get a code if you added the wire for it that the 7’s didn’t have? It was my understanding that if you used your normal external harness it didn’t even know it was there and no code would come active.
According to the "Allison King" -Evan. He told me yesterday that if you put an early 01-02 trans in an 05 truck, the 05 truck would be looking for the missing G solenoid and set a Phantom Code. But that the trans would still work and you could disable that code with EFI Live.

So if the 04.5-05 LLY had the G-Solenoid and you put a trans from a truck that didn't have it, It would report that code.

I recall Mike say something to that effect too but I am not sure what post it was in.
 

2004LB7

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According to the "Allison King" -Evan. He told me yesterday that if you put an early 01-02 trans in an 05 truck, the 05 truck would be looking for the missing G solenoid and set a Phantom Code. But that the trans would still work and you could disable that code with EFI Live.

So if the 04.5-05 LLY had the G-Solenoid and you put a trans from a truck that didn't have it, It would report that code.

I recall Mike say something to that effect too but I am not sure what post it was in.
I'm not aware of any method of disabling codes in the TCM with efi live. And the only code in the ECM is going to the the P0700
 

1FastBrick

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I'm not aware of any method of disabling codes in the TCM with efi live. And the only code in the ECM is going to the the P0700

Apparently it throws a code for the G solenoid mabe on the TCM side.

 

2004LB7

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Apparently it throws a code for the G solenoid mabe on the TCM side.

Didn't see anything about disabling codes????. Good info in that first link but no discussion about turning off the code
 

1FastBrick

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I'm not aware of any method of disabling codes in the TCM with efi live. And the only code in the ECM is going to the the P0700
Didn't see anything about disabling codes????. Good info in that first link but no discussion about turning off the code

Maybe you 0 out the tables or something for the G solenoid? I am No Tuner...
Maybe some of them have edited the code tables with CAX files in the background???

It's really a shame EFI never really finished looking for more tables and adding the Diagnostic portion to the trans side.


G solenoied.JPG
 

2004LB7

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Maybe you 0 out the tables or something for the G solenoid? I am No Tuner...
Maybe some of them have edited the code tables with CAX files in the background???

It's really a shame EFI never really finished looking for more tables and adding the Diagnostic portion to the trans side.


View attachment 114643
Definitely would've been nice to have more development for the Allison tuning. So much more potential left on the table. But I guess what we got was good enough for 99% of the people that tune the transmission. And 99% doesn't even touch it. So a very small market for sure

It's been awhile since I tuned one. But my recollection was that none of the codes where editable like in the ECM. So as you say, if anyone's doing it, it's probably HEX editing or CAX files. But as an alternative, couldn't you just wire in a low ohm resistor to the TCM pins where the G solenoid would normally go?
 
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