10Lxx vs 8Lxx vs 6Lxx Replacement for 4L65

[S33k3r]

I have a 4L65e -- on the 2004 Escalade ESV -- that needs to be refurbished/replaced. However, I've been a bit spoiled by the smoothness of the Alison in my 2007 Silverado. Which leads me to ask: Is there anyone that can recommend a 6, 8, or 10 spd upgrade for the 4L65?

There's a company in Houston that is doing the 10L80/90, but for the GMT900+ platforms -- not the GMT800.

Thanks for any help.

 

[drdave81]

I've looked into this before. It's way too much of a PITA as it requires a separate TCM to control it, where our 4L60E is controlled by the PCM. Everywhere I've seen, it was determined to not be worth the hassle if it's even realistically possible. I'm pretty sure the communication bus is different too, so that pretty much rules it out. Just get a GOOD upgraded rebuild on yours and be good to go. I got mine bench built with all the upgraded internals for $1250 by a guy in SE Michigan. Call reputable trans shops and get some prices.

 

[tooleyondeck]

It's technically doable, but is the juice worth the squeeze of needing custom wiring, mounts, and a standalone TCM to run it? I would suggest that you consider a built 4L80.

 

[strutaeng]

There is a guy on the PT.net that tried to swap a 6L80 on his GMT800 Tahoe, but last I heard, he got hung up on the electronics...

Is the Escalade a 2wd? I would also vote 4L80e swap (you probably guessed that from our other conversations on the different threads ).

BTW, I got an Allison 5 speed I'm considering swapping (along with a 8.1 from a 2500HD into my Suburban 2500). I got me some books on how to rebuild them and doesn't seem like a super complicated transmission. I "may" open it up just thinker with it...that's not here nor there...but I just realized something along the line of an Allison 6 speed would be sick on a GMT800 SUV, probably with like a 6.6 gas engine(?)

Edit: here's the thread I was thinking about. It's super long and have never really tried reading all of it or the details: https://www.performancetrucks.net/f...neral-discussion-130/using-tcm-2650-a-559049/

 

[S33k3r]

There is a guy on the PT.net that tried to swap a 6L80 on his GMT800 Tahoe, but last I heard, he got hung up on the electronics...

Is the Escalade a 2wd? I would also vote 4L80e swap (you probably guessed that from our other conversations on the different threads ).

BTW, I got an Allison 5 speed I'm considering swapping (along with a 8.1 from a 2500HD into my Suburban 2500). I got me some books on how to rebuild them and doesn't seem like a super complicated transmission. I "may" open it up just thinker with it...that's not here nor there...but I just realized something along the line of an Allison 6 speed would be sick on a GMT800 SUV, probably with like a 6.6 gas engine(?)

Edit: here's the thread I was thinking about. It's super long and have never really tried reading all of it or the details: https://www.performancetrucks.net/f...neral-discussion-130/using-tcm-2650-a-559049/

FYI, there is a conversion kit to convert the Allison 5 speed into a 6 speed. If necessary, I can always add a 2" body lift to the Escalade. That would allow it to clear the Allison. I guess I'll see what I find out.

 

[S33k3r]

I've looked into this before. It's way too much of a PITA as it requires a separate TCM to control it, where our 4L60E is controlled by the PCM. Everywhere I've seen, it was determined to not be worth the hassle if it's even realistically possible. I'm pretty sure the communication bus is different too, so that pretty much rules it out. Just get a GOOD upgraded rebuild on yours and be good to go. I got mine bench built with all the upgraded internals for $1250 by a guy in SE Michigan. Call reputable trans shops and get some prices.

There are standalone controllers out there, so I guess I'll do a little more research. I'm probably going with a built 4L65e, anyway, but I can dream.

 

[S33k3r]

It's technically doable, but is the juice worth the squeeze of needing custom wiring, mounts, and a standalone TCM to run it? I would suggest that you consider a built 4L80.

I assumed a standalone controller for the transmission would be required. Thanks, though.

 

[justirv]

There are standalone controllers out there, so I guess I'll do a little more research. I'm probably going with a built 4L65e, anyway, but I can dream.

for the 4L60/65/70e I recommend checking out the Sonnax build guides. With the proper parts and builder, these transmissions can still perform.

4L60E HP & HD Transmission Build Guide | Sonnax

Recommended Sonnax parts for 4L60-E series rebuilds make it easy to upgrade heavy-duty and high performance vehicles at any power level for max reliability.

www.sonnax.com

 

[drdave81]

There are standalone controllers out there, so I guess I'll do a little more research. I'm probably going with a built 4L65e, anyway, but I can dream.

There are guys dumping more than 600hp through a well built 60E. What specifically are you looking for? Just more gears?

 

[drdave81]

I'm going to start right off by saying I didn't even read through most of this, so I have no idea how much info is actually in here that you may want. I read the first few posts, then jumped to the end, and despite 30 pages, it looks like no one has been successful with a 6L80E swap yet.

Using a TCM-2650 - PerformanceTrucks.net Forums

GMT 800 & Older GM General Discussion - Using a TCM-2650 - Has anyone on HERE successfully used the controller in the title to swap in a 6l80? I have questions. I'm toying with the idea of ditching the T56 swap for the 6l80. I like having 6 speeds in the truck, i also like rowing the gears too...

www.performancetrucks.net