5 Speed behind an LBZ

[Dudgy]

Here's my deal, i'm dropping a complete 06 LBZ drivetrain into my 03 racetruck, i have a donor truck and am gonna swap all the wiring, engine, everything behind the dash, leather interior etc etc.

Now i already have a built allison 5 speed in the racetruck behind the LB7, can i run that with the LBZ if i just keep that 5 speed TCM?

I did a transgo jr in the 6 speed that's in the LBZ truck, but would need some more parts if i'd swap valvebodies and turn that built trans into a 6 speed right?

Let me know what you guys think, i think 5 gears is plenty for racing haha so i rather keep the 5 speed unless you guys have some different opinions.

Thanks in advance!
Rony

 

[jc1843]

The problem is the 6 speed [LBZ]uses a different operating system that the 5 speed [LB7] And the TCM works with the ECM. So trying to mix the two is almost impossible.

To make the 5 speed into a 6 speed, will require a conversion kit [modified valve body and programmed TCM]

 

[Dudgy]

Ya i have a Tcm and I can pull the valve body from the 06 and do whatever I need to with them. I just need to know exactly what I gotta do to make that work with the built tranny and I guess I will have to run the 6 speed then.

I was also thinking of swapping internals from the built trans to the 6 speed, not all that much work or I'll just get a new kit and start with a fresh trans next season. Hmm decisions decisions lol:rofl:

 

[TeaBagger2006]

Fresh trans doesn't sound bad at all. Sell your 5speed

 

[paint94979]

Fresh trans doesn't sound bad at all. Sell your 5speed

listen to this guy... ^^^^^^^

 

[gmduramax]

The 5 speed and 6 speed are the same trans. Swap valve bodies and I believe the Nuetral safety switch. IIRC

 

[Hot COCOAL]

The way i see it, you have two "viable" options
5 to six speed conversion on the already built 5sp, not cheap
Sell the built 5sp on the forum, and build the 6sp
personally id start fresh with the 6spp, i think you are/would be presenting yourself with little challenges left and right tryin to get your 5sp to work the way you would want it to.

 

[THEFERMANATOR]

The 5 to 6 speed conversion kit will NOT work in this case. If you want to use the 5 speed behind the LBZ, you will have to convert over to the internal mode switch, 6 speed shift shaft, 6 speed valve body, and 6 speed wiring harness. You will also have to use teh 6 speed TCM as there is no known way to make a 5 speed TCM CORRECTLY communicate with the 06+ LBZ ECM. Honestly you would be better off to build the 6 speed though and have the upgraded C1/C2 rotating drum that the 6 speed has, and chanes are unless you have a LATE 05 5 speed you will also get the heavier input shaft and bearing assembly as well as the better planetarys that the trannies built from Feb of 05 on have in them.

 

[THEFERMANATOR]

The 5 speed and 6 speed are the same trans. Swap valve bodies and I believe the Nuetral safety switch. IIRC

Not quite the same, there were ALOT of upgrades/changes in them through the years. But the 6 speed is quite a bit better internally than most of the 5 speeds.

 

[Hot COCOAL]

Why cant you use the conversion kit, forgive my ignorance please. Im not trying to argue for it, i clearly believe the 6sp is the way to go, just curious

 

[duratothemax]

Why cant you use the conversion kit, forgive my ignorance please. Im not trying to argue for it, i clearly believe the 6sp is the way to go, just curious

because the TCM used in the suncoast 5-6speed conversion kit is completely different than a factory 6-speed TCM. 01-05 dmax ECM's will only talk to an allison 3rd gen TCM. 06+ dmax ECM's will only talk to an allison 4th gen tcm.


fermanator explained this in post #8

 

[Dudgy]

Cool thanks all for the help. I'll order some 6 speed goodies and build that one. And try to sell the 5 speed

 

[malibu795]

because the TCM used in the suncoast 5-6speed conversion kit is completely different than a factory 6-speed TCM. 01-05 dmax ECM's will only talk to an allison 3rd gen TCM. 06+ dmax ECM's will only talk to an allison 4th gen tcm.


fermanator explained this in post #8

if thats true...

how does the 6 speed conversion work on the 5speed??

logic would say that if one can get a 6speed to work behidn a lb7/lly then they should be able to get a 5speed behind a lbz and newer

 

[z79outlaw]

if thats true...

how does the 6 speed conversion work on the 5speed??

logic would say that if one can get a 6speed to work behidn a lb7/lly then they should be able to get a 5speed behind a lbz and newer

Its a suncoast conversion its not allison, it still uses the 3rd gen TCM. The 6spds have the 4th gen TCM and cant communicate with the 5 spd, there is a 5spd conversion for the 6spds its called 5 on the tap shifter...

 

[Mike L.]

Solenoids are different and TCM can't learn the TAP value's.