6L80e 6spd Conversion

[High Five H2]

how did you adapt it to your crossmember?

 

[adventr]

Dextron 6. Only

Main spare part for my Hummer while off-roading - sattelite phone !

Thanks! That makes it easy.

 

[adventr]

how did you adapt it to your crossmember?

Well, using the stock mount that came with my 6L80e, it literally just bolted right up to the holes (slots) in the H3 crossmember. Easy as that.

 

[rsc]

I am so jealous!

 

[humvee]

This is amazing!

 

[Mb30sdl]

Man oh man I hope this works out! I could really use a better trans in my T!

3 transmissions don't lie... The 5.3 with super charger and 37s is too much for the 4L60e!


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BS I build 4L60 to handle 500+ With 40"s ( not cheap but well worth it)
White T is getting upgrade in next couple of weeks, it's TC I am worried about. And it will be getting a blower and 40s before next summer.

 

[RamRod]

BS I build 4L60 to handle 500+ With 40"s ( not cheap but well worth it)
White T is getting upgrade in next couple of weeks, it's TC I am worried about. And it will be getting a blower and 40s before next summer.

Calling BS on what? The 3 transmissions?

Don't be calling me out unless you have something to back yourself up.

 

[Mb30sdl]

I own AAMCO if you build it to "competition specs" ~$2500 (parts only)for me (~6500 for plain customer)it will hold 500+HP. Your blower is ~420hp. I have done it on GMC when I got it and 2 years later it has no issues.

plus TC is a pos that will go first. 2 trucks 4 TC.

 

[amrg]

I think at that price (6500) its cheaper to do a 6 speed conversion as it holds 500 hp on lots of cars/trucks...

 

[adventr]

I own AAMCO if you build it to "competition specs" ~$2500 (parts only)for me (~6500 for plain customer)it will hold 500+HP. Your blower is ~420hp. I have done it on GMC when I got it and 2 years later it has no issues.

plus TC is a pos that will go first. 2 trucks 4 TC.

No doubt you can build a 60e to hold the power. But then you have $6500 in a 4spd transmission. 6L80e will hold the power, and have 2 more gears. And it's WAY cheaper.

 

[Mb30sdl]

U have seen spread 1-2? It's almost doubles. The only gain is top speed 5-6 is very close. I have both of this set ups and I don't see any difference in driving.

we see about same in numbers in these tranis coming to the shop for rebuilds.

price wise: how much is used 80? I guess ~$1500/2000 add rebuild (cheap one is ~$3000/ good $6k) plus easy plug and play ? (Guessing ~$500/1000) TC used ~1k= $6k/10k where is savings?

 

[rascole]

All this talk of the 6 speed, why not the new 8 speed? 4.56 vs 4.02 first gear is a better crawl ratio, the 4 speed has a 3.06. If your going big then might as well go for the 8 speed right? 83 to 1 crawl ratio, stock is 55 to 1. That's a huge jump. I'm not a transmission guy or a fabricator but just my 2 cents.

 

[amrg]

Point is to have it as p&p as possible (8 speed is fairly new and not sure if there is someone providing a kit)
Offcourse more gears will help, but atm it would he easier to find a low mileage good 6l80e in the scrap yards.
Anyway, with stock tires the first gear on 8 speed would be too low (making it almost useless and as a result an alpha will need to be regeared to 3.xx gears rather than the 4.10 - as in the pickups - or you will be starting from 2nd)

Numbers wise, a 6 speed puts an alpha with 37s slightly better than an alpha with 4 speed on 32s (how mine was) and you will get an even lower over drive gear (6th).

 

[High Five H2]

I'd stick with a 6 speed even if there the 8 speed was available. With 8 speed, you gain a bit of fuel economy, but you lose some power. Check out the difference between the '14 and '15 performance numbers for silverado pickups. '14 has the newer DI engines and a 6 speed, but the '15 gets the 8 speed. There's a pretty substantial jump in fuel economy in '15, but the 1/4 mile times and 0-60 times are lower by .3 seconds or so each.

 

[adventr]

Just an update:



Got the transmission installed and filled up the other night. Fired it up and Reverse gear worked great. Nothing when in any of the Forward gears. Everyone says thats a communication protocol issue between the 2011 transmission OS and my h3 2009 OS.

So, got a GM technician buddy to come by today and reflash my transmission (TCM) to a compatible OS. Tried it 4 different times, and it always error'd out at the very end.

Now, nothing works... TCM is a brick. It won't even let me take it out of Park now, and engine light is on showing no communication with TCM.



So.......... in the process of trying to find out which TCM/Valvebody part number to order. Don't want to brick anything else; at $500 each, those TCMs get expensive.

 

[Ghostbuster]

Wow that sucks

 

[Bigunit]

Oh man, hope it all works out for you. You are blazing a new trail and I'm pulling for and following your conversion with a lot of interest. Good luck.

 

[Mr_Rich]

Just an update:



Got the transmission installed and filled up the other night. Fired it up and Reverse gear worked great. Nothing when in any of the Forward gears. Everyone says thats a communication protocol issue between the 2011 transmission OS and my h3 2009 OS.

So, got a GM technician buddy to come by today and reflash my transmission (TCM) to a compatible OS. Tried it 4 different times, and it always error'd out at the very end.

Now, nothing works... TCM is a brick. It won't even let me take it out of Park now, and engine light is on showing no communication with TCM.



So.......... in the process of trying to find out which TCM/Valvebody part number to order. Don't want to brick anything else; at $500 each, those TCMs get expensive.

I want to applaud you for even attempting a project like this. The problem I have is that when I read up on this trans it doesn't have a manual gear selector; it's all electronic. As much as it seems like a cool project for a road vehicle it seems like a nightmare for an off-road vehicle; too much complication.
This comes at a time when I may need to drop the trans in my old truck, but I think the only option is to repair what I have and not even think about any later conversions.
Sometimes the answer comes to you the next morning after a good rest. I'm hoping you'll get it sorted out soon!

 

[Ryan212]

Do you have tuning software?

 

[adventr]

Thanks for the support guys! I'll get it figured out eventually. Lol

So we're all pretty confident that this next option is going to work. I mean, it pretty much has to! I think.

Ordered the valve body/tcm for a 2009 year vehicle with the 6L80e.
Therefore.. It should have no problem accepting the 2009 vin number that I'm feeding it for the OS flash. The vin I'm using is for a 2009 Denali.

The new tcm will be delivered at my house on Saturday! Soon as it gets here, I'll run it over to my guy's house where he can bench flash it with the wiring harness he has. He's using a GM MDI tool and the GM website where it pulls the actual OS based on vin number.

Got my fingers crossed. Would love to drive this thing again soon. When I had it fired up today, it reminded me how much I love the sound of that engine with the black widow exhaust.

 

[adventr]

Do you have tuning software?

I have hp tuners to do all of the shift point tuning and everything.
Before I bricked this tcm, I was able to pull it's stock tune so that I can familiarize myself with all the new 6spd parameters in the T43.

My gm buddy is using the GM MDI interface to do all of the OS flashing. This new tcm that I ordered is the same part number listed under the 2009 VIN that I'm using for the OS. So I would assume there would be no issues loading the new OS... Well, hoping anyway.


Interesting note, my gm guy said he's bricked a few, but they've always error'd out way early in the flash. This one would only error out after being 100% done with the actual flash. It would error out after bringing the pcm back online. I say that because I would hear the throttle body cycle and stuff, then like 15 seconds later it would beep. Then start all over and try again.

 

[Ryan212]

The brick at the last step is the difference in the last 8 bytes being written to the one vs the bootloader programming the last 8 bytes itself.

You will need an ecm on the bus or terminate the can bus with a 120 ohm resistor to flash a tcm on a bench harness

Good luck

Ryan

 

[adventr]

The brick at the last step is the difference in the last 8 bytes being written to the one vs the bootloader programming the last 8 bytes itself.

You will need an ecm on the bus or terminate the can bus with a 120 ohm resistor to flash a tcm on a bench harness

Good luck

Ryan

So that last part, were we doing something wrong, or was that just going to happen either way?

I'll check and see if his harness has a terminating resistor. If not, I think I still have one left over from my VGT turbo controller project on another vehicle. Thanks for the info.


Just curious, do you see anything wrong with what I'm planning to do? Use new tcm and flash with 09 vin OS?

 

[Ryan212]

You did nothing wrong other than cross the 2 types of t43 controllers. 2009 and older and 2011+ with 2010 being a mixed year some using the older style and some new style.

The pcm uses a bootloader to reflash. The last 8 bytes are used to tell the tcm that it has a valid calibration file present.

A 2009 tcm and reflash should be fine. The tcm module you have should be able to be recovered if you reflash a 2010+ file back into it.

Ryan

Ryan

 

[adventr]

You did nothing wrong other than cross the 2 types of t43 controllers. 2009 and older and 2011+ with 2010 being a mixed year some using the older style and some new style.

The pcm uses a bootloader to reflash. The last 8 bytes are used to tell the tcm that it has a valid calibration file present.

A 2009 tcm and reflash should be fine. The tcm module you have should be able to be recovered if you reflash a 2010+ file back into it.

Ryan

Ryan

Awesome, you certainly know more about this stuff than anyone I've spoken with!

So on that termination resistor, it just goes across the 2 canbus wires right?

And I'll have to try putting a 2011 vin on that tcm. At least if it's working again it might be useful to someone!