Seattle_Diver

Hi all. Brand new to the group.

I am doing a swap to a 376ci LS3 and a 4l70e transmission. I have an E67 controller (I am getting the whole kit from Blueprint Engines).
My big question, which I am having a really hard time finding out the answer to is: "What do I need to do to control my shifting in the trans with paddle shifters?".

I see that there are controllers out there that let you control everything like the shift points and timing, etc. I have no desire to do all of that. I just want basic up shifting and downshifting.
My gut tells me that there is an input into the ECU that I can plug into and do it easily, but I cannot find proof of that.

All help is appreciated!

Scott

mrvedit

First the E67 ECM is ONLY the engine controller; it does not control the transmission. You will also need a Transmission Control Module (TCM). The T42 TCM controls the 4L70E, but I don't think the E67 easily/directly supports the T42/ ???
Hopefully someone can educate me too - does the E67 ECM directly support the T42 TCM? As I understand, the E67 works on the CAN bus while the T42 only support the older serial bus.
If not, you might ask Blueprint for an E40 ECM which does work with the T42 PCM.

On a quick search I could not find definite answer on whether a T42 supports paddle shifters. There are older (15 year old) posts about using aftermarket TCMs with paddle shifters, but their transmission control is primitive compared to a T42.
Hopefully someone will have a definitive answer and if positive, perhaps a link on how to do it.

CattleAc

iTrader: (7)

Maybe try asking down here in the...Auto trans section

The guys that hang out down there are VERY sharp.

mrvedit

Good point. I will move it tomorrow; maybe someone here wants to add to it first.

mrvedit

Guys, I moved this thread from the "Conversions and Swaps" section, where as of recently I am now the main (only?) active moderator.

Hopefully someone can give this new guy a good answer and also answer my question in post #2 about whether the E67 can support the T42 TCM.

MaroonMonsterLS1

the E67 was used in TBSS and Envoy Denali etc
So it is definitely compatible with the T42

And the t42 can paddle shift no problem.
Check out 05 corvette segment for paddle shifting

If you want to paddle shift safely/reliably you'll need to hydraulically modify your 4l60e
Multiple ways to achieve this modificaiton. You can match it to the factory 05 corvette hydraulics, you can use a sonnax HD 2-3 shift valve, or you can modify the vb with a drill bit and a couple slugs of solder (this is how I do it and similar to how frank does it)

Seattle_Diver

Thanks for the reply. Two questions:
1. Why doesn't the 4L70e shift safely already? What does the change do?
2. Do you know where I could learn more about those mods?

I think I will be using the Lokar electronic automatic sport shifter for auto or manual.

Seattle_Diver

Ok I searched for sonnax HD 2-3 shift valve and read about it. Step 1. of the install looked easy. Step 2. looks scary as hell for a guy who has never worked on transmissions. I really need to drill a hole in it? It seems like if I screw that up I am going to trash the whole transmission.

mrvedit

I understand your concern as this mod is not easily reversible. Instead of drilling, I prefer to use strong cutters to cut a groove there; IMO its cleaner without spreading metal bits.
The alternative is what the pros here call the "overrun mod" which involves only modifying the separator plate; so it reversible with a new separator plate.
See posts #2, #7 and #9 in this recent/ongoing thread: https://ls1tech.com/forums/automatic...-everyone.html
I've seen more detail about the "overrun" mod, but currently cannot find it. Perhaps someone could like to it.

pdxmotorhead

How is the paddle shift function different than the factory "tap to shift" function all it does is lock out automatic shifting to allow for towing in lower gears..?

I have my 4l65E using the manual shift side of a lokar via a Terminator X max but the original question got me wondering......

MaroonMonsterLS1

the factory 05 vette applies the overruns when pulled into "M" mode for paddle shifting
That's prettymuch a requirement for doing this "safely" as asked above.
Any 4l60e that didn't come out of an 05 vette won't hydraulically apply the overruns like it should for paddle shifting unless you modify it to do so.

Seattle_Diver

Sorry to keep asking questions, but I want to make sure I understand this. Two questions:
1. What happens if you don't make those changes and you shift manually?
2. Worst case scenario - I mess up drilling it. Does that trash the whole trans? I don't expect messing it up but I am an engineer so I like to know what parameters I'm working with.

MaroonMonsterLS1

What happens is you won't have "engine braking" in 1st, 2nd, or 3rd
It'll freewheel on decel then engage with accel

not only will that feel like crap for paddle shift
it'll also be hard on the input sprag

As for messing it up
If you can manage to get the pan off and the valve body out of the car...you can manage drilling a single hole.
It's about as easy as can be.

y5e06

drilling the hole is pretty easy. the biggest concern would be letting chips into the valve body, especially if it is still oily. They will just stick everywhere. I think this is why side cutter action is mentioned above.
I've done a handful of these and always start with a fully disassembled and cleaned VB, and then reclean it after the 2-3 shift valve & drlll mod and TCC reaming (sonnax).