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6T75 6 speed conversion

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Old Jan 19, 2011 | 12:11 PM
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Default 6T75 6 speed conversion

We are currently working on fabbing some tranny mounts to market in the future, any ideas, requests or contributions from the community?

Let us have it!!
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Old Jan 19, 2011 | 12:14 PM
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We need a custom mount for the starter too. LS4s have transmission mounted starters.
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Old Jan 19, 2011 | 12:32 PM
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We're on track with the starter mount area of the project. (edit) Although, the bell housing can be milled to fit the starter, we are going to fab an adapter plate for a friendly bolt-on conversion....progress, progress.

I think it will be substantial as a simple swap. I've done a little research and it should hold 400-500 whp reliably. My only concern is holding the component substantially with a stiff but comfortable amount of travel. We don't want any broken ears, etc.

We'll probably use some poly and steel and see how it works. We'll be making a mock up for a customer today hopefully, so we'll keep you posted on how progress goes.

If anyone had any under carriage pictures of the starter, tranny, etc. it would help immensely in our R&D!

Last edited by OrlandoMachine; Jan 19, 2011 at 12:43 PM. Reason: Addition
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Old Jan 19, 2011 | 12:45 PM
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Bolt in kit for gxps and Chevy's? Interested.
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Old Jan 19, 2011 | 12:57 PM
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We're working in that direction. Even throwing a nice polish or powder coat on 'em!
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Old Jan 19, 2011 | 02:42 PM
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This is exciting news!

I guess we'll need to start researching how this swap would work with regards to the PCM, as well as what mods the trans will need to reliable handle 280+ lb-ft of torque at the wheels.

Does anyone know of any shops that mod the 6T75, or what parts are available?
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Old Jan 19, 2011 | 03:18 PM
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We'll prob be looking at around $300-$400 for the kit as it stands, general consensus on being worth the battle?

-Bell housing adapter plate
-Starter mounting plate
-Transmission bottom side mount (poly bushings)

And other misc. items.

Although the kit is bolt on, we will more than likely have to machine the housing of the tranny itself to accept the starter's location, i.e. hone an area for the flex plate and starter gear to meet. Thus, additional expenses will need to be done.

To compete with that idea, we could have the tranny shipped to us, do the work and mount the plates, starter, etc.

Thoughts?

Last edited by OrlandoMachine; Jan 19, 2011 at 03:25 PM. Reason: Addition
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Old Jan 19, 2011 | 03:39 PM
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Originally Posted by OrlandoMachine
We'll prob be looking at around $300-$400 for the kit as it stands, general consensus on being worth the battle?

-Bell housing adapter plate
-Starter mounting plate
-Transmission bottom side mount (poly bushings)

And other misc. items.

Although the kit is bolt on, we will more than likely have to machine the housing of the tranny itself to accept the starter's location, i.e. hone an area for the flex plate and starter gear to meet. Thus, additional expenses will need to be done.

To compete with that idea, we could have the tranny shipped to us, do the work and mount the plates, starter, etc.

Thoughts?
Shipping a trans back and forth could easily double the cost of the swap, depending upon the location of the owner. And that's not even counting what your shop would (rightfully) charge for the additional machine work. For a money-is-no-object situation, or someone living in the southeast, taking it to your shop is probably a no-brainer. For many of us, it might be cost-prohibitive.

Perhaps you could include very specific machining instructions/specifications so that those of us unable to ship the trans could take it to a local shop for the work.

Just a suggestion.

That said, $300 to $400 for the kit sounds VERY reasonable to me!
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Old Jan 19, 2011 | 03:51 PM
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Found this on ebay:

http://cgi.ebay.com/ebaymotors/HYDRA...Q5fAccessories

Granted, this is the AWD version, and the non-AWD model may even be cheaper.

This is much less than what I thought the trans would cost, and it will probably only come down more as they become more common.

Now it's a question of software and strengthening upgrades.

This is pretty encouraging, because a decent street trans from TEP is $1650, plus shipping. Add in another $200 for a rebuilt converter, $200-$300 for shipping, then another $400 to install, you're at $2500 and you still have an ancient 4-speed.

If this swap can be put together for comparable money, then the LS4 community will finally have a viable alternative to rebuilding a stocker.
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Old Jan 19, 2011 | 03:55 PM
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https://ls1tech.com/forums/ls4-front...onversion.html

The title is supposed to be 6T75, some info in there, been lurking for a little while.
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Old Jan 19, 2011 | 05:54 PM
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Originally Posted by OrlandoMachine
We're on track with the starter mount area of the project. (edit) Although, the bell housing can be milled to fit the starter, we are going to fab an adapter plate for a friendly bolt-on conversion....progress, progress.

I think it will be substantial as a simple swap. I've done a little research and it should hold 400-500 whp reliably. My only concern is holding the component substantially with a stiff but comfortable amount of travel. We don't want any broken ears, etc.

We'll probably use some poly and steel and see how it works. We'll be making a mock up for a customer today hopefully, so we'll keep you posted on how progress goes.

If anyone had any under carriage pictures of the starter, tranny, etc. it would help immensely in our R&D!
Thanks for posting this. As you can see, the interest is definitely there!

To all: Anyone who has been following this section over the past few years would know that I am a big proponent of this swap. In fact, I've been into it the moment I heard GM and Ford were developing this transmission. So much so that I've been all over the map looking for someone to work it out. I still don't understand why GM didn't/doesn't put this transmission in a W-body.

Regardless, I am the customer that he speaks of and I am eager for this to be completed.

Most of the mods I try to get going are for stock cars. So there aren't any guarantees that this will work with the headers' crossover as I don't have headers. This transmission could easily sit higher or lower than the 4T65E-HD. Time will tell.

Originally Posted by LS1 Racing
This is exciting news!

I guess we'll need to start researching how this swap would work with regards to the PCM, as well as what mods the trans will need to reliable handle 280+ lb-ft of torque at the wheels.

Does anyone know of any shops that mod the 6T75, or what parts are available?
It should handle it fine. Remember that this transmission sits behind almost 5,000 lbs full-size crossover SUVs. I say build it if anyone's making some serious power (over 500 HP/TQ). Also, our vehicles have ECMs and TCMs versus a single PCM.

The research is pretty much done. A module already exists that will mate the E40 and E67 ECMs to the T43 TCM ([literally] found inside the new clutch-to-clutch 6 speed transmissions: 6T70/75, 6L80/90, etc.).


Originally Posted by LS1 Racing
Found this on ebay:

http://cgi.ebay.com/ebaymotors/HYDRA...Q5fAccessories

Granted, this is the AWD version, and the non-AWD model may even be cheaper.

This is much less than what I thought the trans would cost, and it will probably only come down more as they become more common.
Actually, they can be had for just over half that price.


Originally Posted by LS1 Racing
That said, $300 to $400 for the kit sounds VERY reasonable to me!
Indeed, but there's going to be a little more added to that which hasn't been discussed: module and half shafts.

EDIT: More info on the 6T75 courtesy of FastFieros: http://www.filedropper.com/6t75

FYI: The picture in the document is of the 6T70 and not of the 6T75; the 6T70 will bolt to our engines without an issue.

ECM identification: http://www.lt1swap.com/pcm_identification.htm

Last edited by GXP25; Jan 19, 2011 at 05:58 PM. Reason: Added some more info.
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Old Jan 19, 2011 | 06:47 PM
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This is awesome news. I'd still own my Impala if it had a 6 speed tranny.
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Old Jan 19, 2011 | 06:56 PM
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6 speed would be sick. anyone know what a total cost would be for EVERYTHING needed to turn an ls4 to 6speed?
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Old Jan 20, 2011 | 12:04 AM
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mabey we could put a slick on here and not have to worry about it yeah i want one
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Old Jan 20, 2011 | 01:26 AM
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man i will get on board with this sounds bad a$$
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Old Jan 20, 2011 | 04:24 AM
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Im deffinetly game for helping out... I was just thinking the other day that this would be a perfect choice for my ls4 fiero mod...
I will try to help out as much as I can from here...
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Old Jan 20, 2011 | 05:20 AM
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I could definitely get down with this...
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Old Jan 20, 2011 | 02:36 PM
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I love the interest. Out the door, computer, adapter plates, module, etc. what would everyone be looking to pay. Basically, everything minus the trans.
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Old Jan 20, 2011 | 02:51 PM
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Originally Posted by Battle_Ravage
https://ls1tech.com/forums/ls4-front...onversion.html

The title is supposed to be 6T75, some info in there, been lurking for a little while.
It says in the thread an adapter plate for the bell housing exists, any info?
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Old Jan 20, 2011 | 03:00 PM
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looking at the gear ratios, so i take it first gear will be disabled

and will the TAP shift work with the conversion
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