blindawg

Pretty sure you can only mix/match truck OS and trans OS between 07-09 and 10-13ish. Meaning your truck won’t accept the 2010 tcm. You’re gonna have to put a tcm from 07-09 in it and flash it with a VIN from 07-09 vehicle.
Same thing happened to me, trans was supposedly out of an 08, but it had a 2010 tcm in it. Have fun with that extra $600 item/flash. Lol.

orlandoavalanche

OK guys i just finished my swap so wanted to add to this as i used this thread to get some good info..
I did the swap in a 2007 new body style avalanche 4x4 with NON all wheel drive transfer case ( dial for 4wd -2wd )
came with a 4l60 and a 5.3 but i changed motor out for a 6.0, straight cam ( no dod or Valve timing BS ) and high compression heads ( small chamber ) last year, truck dyno at 315hp with well over 425 torque RWHP with 33x12.5 / 20s tires and old trans

This is a pretty direct bolt in application and only thing is wiring change..

First what you need to get:
Obviously a 6l80 trans from wherever,
If you have 4wd you need to get the trans to transfer case spacer from an 6l80 as that is what makes the driveshaft lengths the same as the 4l60 ( spacer is 1.75 shorter on 4l )
Order trans electrical plug from amazon ( Chinese **** works ) Also look up plug pin wire location ID schematic ( found easily online )
Order a dipstick and tube from any sierra, avalanche, gm truck from 2007 and newer.. ( i bout original GM parts )
If you have 4wd NP241 transfer case ( not all wheel drive ) then you will need to get a new input shaft for the NP246 transfer case ( 32 spline ) about 40 bucks online..
You need shifter cable bracket for the 6l80 as the 4l60 is different but cable are same..
Have someone with access to wiring diagrams from your year vehicle- GM gives every year the wiring diagram for all the transmissions they make. ( at least my guy did ) Example- my truck for 2007 did not come available with a 6l80 but there is a wire schematic for that year when you look up the vehicle and that is the diagram you will follow to wire your truck.

Ok now for the most difficult part but kinda easy if you can think a little outa the box..

WIRING INSTRUCTIONS
GM was pretty good keeping the diagrams easy to read. When you look at diagram there are circuit numbers and pin number location to identify what the wires are for.
EXAMPLE
replicated TOS signal - 6399 - pin 16
ignition voltage - 2139 - pin12
Now a total of 11 wires need to be run for the new transmission plug. ( or at least in my case )
THIS IS WHAT I DID TO MAKE THINGS EASY:
I took a sheet of paper and made columns for:
new trans plug wire number to circuit and pin number( look at back of the new trans plug for numbers as its stamped on it ) these wire colors do not match anything so dont go by colors..
old TCM plug pin # wire location
circuit number and color of wire old TCM and pin number
Jumper wire needed. This is the original wire from old trans plug being used to connect up at the old TCM.. Example is you might take a pink wire and connect it to the blue wire at the old TCM plug to get that wire to the new trans plug. New plug is on trans where old TCM plug is by battery in engine compartment.. we call this a jumper or substitute wire so you do not have to run new wire harness.

Ok so in my application I butt spliced 9 wires at the old TCM location and had the others all ready existed at the trans from old transmission plug.. now there are two things that will confuse you and that is the serial data bus + and - at the old TCM location you will have data from PCM and TCM + and -( 2 wires for + and 2 for - ) You will splice both + to a jumper and both - together to a jumper to bring it to new trans plug. the rest is pretty easy if you make a paper with columns and read the schematics..

Wiring all together top of truck and trans location took me about an hour plus as i checked it over and over..

You will have wires left over at old TCM and at the Old trans plug harness so just tape them up and forget them..

The New tranny install went pretty damm straight forward as everything is straight bolt in.. and the transfer case input shaft was easy as well to do.

I had my trans professionally rebuilt and all the bells and whistles done to it.. Cost 2800 with new billet converter, $125 for trans purchase
Weld 3,4,5, drum
zipkit
raybestos clutches and a bunch of other stuff done to valve body ETC ETC....
Look up online the trans and you will se all that goes wrong with them. I got my trans from a 2010 escalade

Now for the biggest question i have seen on here..

TECHUM OS STUFF
The techum from my junkyard trans was for a 2010 application, my truck is a 2007. from my understanding there is a OS system difference around the 08 to 09 years where the truck ECM OS ( operating system ) will not communicate with the wrong year of OS.. So basically what i did was i went online and looked for a 2007 escalade for sale and got the VIN for it ( Cars.com i think shows vin numbers ) then i ordered a Techum using that VIN and then i had the programmer use the same VIN to download the OS to it.. NO PROBLEMS AT ALL...

OK now after all was in and done i drove my truck and there is a very noticeable difference in the truck pick up from a dead stop. I pull a very big and heavy trailer and it pulls it nicely. I havent been able tboput gas mileage increase but i think i may gain 1 to 2 miles per gallon. old trans got me about 11 to 12 MPG.. Was this worth it.. well my old trans had 265,000 miles and was never rebuilt and it blew up on me towing my trailer right by my house. So to do this upgrade i probably spent an extra 1,000 so very happy with results if the trans holds up to me trailering with it.

orlandoavalanche

OK guys i just finished my swap so wanted to add to this as i used this thread to get some good info..
I did the swap in a 2007 new body style avalanche 4x4 with NON all wheel drive transfer case ( dial for 4wd -2wd )
came with a 4l60 and a 5.3 but i changed motor out for a 6.0, straight cam ( no dod or Valve timing BS ) and high compression heads ( small chamber ) last year, truck dyno at 315hp with well over 425 torque RWHP with 33x12.5 / 20s tires and old trans

This is a pretty direct bolt in application and only thing is wiring change..

First what you need to get:
Obviously a 6l80 trans from wherever,
If you have 4wd you need to get the trans to transfer case spacer from an 6l80 as that is what makes the driveshaft lengths the same as the 4l60 ( spacer is 1.75 shorter on 4l )
Order trans electrical plug from amazon ( Chinese **** works ) Also look up plug pin wire location ID schematic ( found easily online )
Order a dipstick and tube from any sierra, avalanche, gm truck from 2007 and newer with 6l80.. ( i bout original GM parts using the VIN from my techum order )
If you have 4wd NP241 transfer case ( not all wheel drive ) then you will need to get a new input shaft for the NP246 transfer case ( 32 spline ) about 40 bucks online..
You need shifter cable bracket for the 6l80 as the 4l60 is different but your cable will be same..
Have someone with access to wiring diagrams from your year vehicle- GM gives every year the wiring diagram for all the transmissions they make. ( at least my guy did ) Example- my truck for 2007 did not come available with a 6l80 but there is a wire schematic for that year when you look up the vehicle and that is the diagram you will follow to wire your truck new trans.
MAKE SURE YOU GET BOTH 4L60 AND 6L80 DIAGRAMS FOR THE SAME YEAR AS YOUR TRUCK..

Ok now for the most difficult part but kinda easy if you can think a little outa the box..

WIRING INSTRUCTIONS
GM was pretty good keeping the diagrams easy to read. When you look at diagram there are circuit numbers and pin number location to identify what the wires are for.
EXAMPLE
replicated TOS signal - 6399 - pin 16
ignition voltage - 2139 - pin12
Now a total of 11 wires need to be run for the new transmission plug. ( or at least in my case )
THIS IS WHAT I DID TO MAKE THINGS EASY:
I took a sheet of paper and made columns for:
new trans plug wire number to circuit and pin number( look at back of the new trans plug for numbers as its stamped on it ) these wire colors do not match anything so dont go by colors..
old TCM plug pin # wire location
circuit number and color of wire old TCM and pin number
Jumper wire needed. This is the original wire from old trans plug being used to connect up at the old TCM.. Example is you might take a pink wire and connect it to the blue wire at the old TCM plug to get that wire to the new trans plug. New plug is on trans where old TCM plug is by battery in engine compartment.. we call this a jumper or substitute wire so you do not have to run new wire harness.

Using both 4l60 and 6l80 schematics figure out where the 11 wires are that you need to use from old to new.

Ok so in my application I butt spliced 9 wires at the old TCM location and had the others all ready existed at the trans from old transmission plug.. now there are two things that will confuse you and that is the serial data bus + and - at the old TCM location you will have data from PCM and TCM + and - ( 2 wires for + and 2 for - ) You will splice both + to a jumper and both - together to a jumper to bring it to new trans plug. the rest is pretty easy if you make a paper with columns and read the schematics..

Second thing is there are 2 wires that come from the ECM.
So those wires go to the old TCM plug so those will need jumpers.. but study the schematics and go over it several times to figure it out....



Wiring all together top of truck and trans location took me about an hour plus as i checked it over and over..

You will have wires left over at old TCM and at the Old trans plug harness so just tape them up and forget them..

The New tranny install went pretty damm straight forward as everything is straight bolt in.. and the transfer case input shaft was easy as well to do.

I had my trans professionally rebuilt and all the bells and whistles done to it.. Cost 3300 with new billet converter and techum, $125 for junk trans purchase
Weld 3,4,5, drum
zipkit
raybestos clutches and a bunch of other stuff done to valve body ETC ETC....my trans was 100% torn down
Look up online the trans and you will se all that goes wrong with them. I got my trans from a 2010 escalade

Now for the biggest question i have seen on here..

TECHUM OS STUFF
The techum from my junkyard trans was for a 2010 application, my truck is a 2007. from my understanding there is a OS system difference around the 08 to 09 years where the truck ECM OS ( operating system ) will not communicate with the wrong year of OS.. So basically what i did was i went online and looked for a 2007 escalade for sale and got the VIN for it ( Cars.com i think shows vin numbers ) then i ordered a Techum using that VIN and then i had the programmer use the same VIN to download the OS to it.. NO PROBLEMS AT ALL...

OK now after all was in and done i drove my truck and there is a very noticeable difference in the truck pick up from a dead stop. I pull a very big and heavy trailer and it pulls it nicely. I haven't been able to figure out gas mileage increase but i think i may gain 1 to 2 miles per gallon. old trans got me about 11 to 12 MPG.. Was this worth it.. well my old trans had 265,000 miles and was never rebuilt and it blew up on me towing my trailer right by my house. So to do this upgrade i probably spent an extra 1,300 so very happy with results if the trans holds up to me trailering with it.