Allison tech info

[MaxPF]

Hello all,

I am doing a standalone swap and I scored a 2007 6 speed Allison from a wadded up DMax truck with 21k miles on it to use behind my fairly tame 12V Cummins.

I have an 01 5 speed TCM and wiring harness, matching NSBU (2 plug jobbie to match the harness), and I will be using an SAE #3 bellhousing with the TC speed sensor. I want to use the 5 speed TCM because I have it, and because it is relatively simple to run stand alone. From what I have been able to learn, nobody has gotten a 6 speed TCM to run standalone, mainly due to the difficulty in getting a suitable OS from Allison without an OE application

So, since I have a 6 speed trans and a 5 speed TCM, I have a few questions. First off, do the 6 speeds have the same internal wiring and solenoid shift combos as the 5 speeds? I.e., does solenoid D on give you 1st, none on 2nd, C on 3rd, C and E 4th, E 5th, D and E reverse, and all on for P/N?

Second, THEFERMANATOR told me that the G solenoid can be left disconnected without any adverse effects. Not that I dont trust him but I wanted to verify that with Mike.

Finally, the last question is one of curiosity since my manual only covers 5 speeds: Assuming the solenoid combos for 1-5 on the 6 speed are the same as a 5 speed, what solenoid combo gives you sixth

Thanks!
Greg

 

[bullfrogjohnson]

The six speeds have a completely different tcm and also different internal harness and valve body.

 

[duratothemax]

Hello all,

I am doing a standalone swap and I scored a 2007 6 speed Allison from a wadded up DMax truck with 21k miles on it to use behind my fairly tame 12V Cummins.

I have an 01 5 speed TCM and wiring harness, matching NSBU (2 plug jobbie to match the harness), and I will be using an SAE #3 bellhousing with the TC speed sensor. I want to use the 5 speed TCM because I have it, and because it is relatively simple to run stand alone. From what I have been able to learn, nobody has gotten a 6 speed TCM to run standalone, mainly due to the difficulty in getting a suitable OS from Allison without an OE application

So, since I have a 6 speed trans and a 5 speed TCM, I have a few questions. First off, do the 6 speeds have the same internal wiring and solenoid shift combos as the 5 speeds? I.e., does solenoid D on give you 1st, none on 2nd, C on 3rd, C and E 4th, E 5th, D and E reverse, and all on for P/N?

Second, THEFERMANATOR told me that the G solenoid can be left disconnected without any adverse effects. Not that I dont trust him but I wanted to verify that with Mike.

Finally, the last question is one of curiosity since my manual only covers 5 speeds: Assuming the solenoid combos for 1-5 on the 6 speed are the same as a 5 speed, what solenoid combo gives you sixth

Thanks!
Greg

you cant just "turn solenoids X and Y" on and it will magically go into 6th gear. Thats not the way the allison works (its not a 4L80 or dodge trans ). You will not be able to make 6th gear work without an actual TCM that has 6-speed software in it.

 

[SmokeShow]

I took it as him questioning about using his 6-speed Allison as a 5-speed using his 5-speed wiring/TCM to control it??

 

[Mike L.]

You will have to use a 5 speed valve body and harness with 5 speed linkage and shaft.

 

[THEFERMANATOR]

There IS a way to get a 6 speed to work as a stand-alone, but it ISNT cheap. It would require getting the SUNCOAST 6 speed conversion kit and the DESTROKED kit and hooking it up that way. Basically you would have to convert your 6 speed back to a 5 speed by changing out the shift shaft, internal harness, and switching over to the external NSBU switch. Then you would have to swap in the 6 speed conversion valve body and TCM. The DESTROKED box would provide the basic needed inputs for the TCM to function, so it IS possible to get a 6 speed to work stand-alone(just not practical really due to the cost). And the G solonoid can be bypassed and left unhooked if you have the correct calibration in your TCM to ignore it(LB7 calibration). If you need a new valve body now, all you can get are ones with the G solonoid as ALLISON no longer makes ones without it. GM has a TSB out on this matter as well.

 

[MaxPF]

You will have to use a 5 speed valve body and harness with 5 speed linkage and shaft.

That is a major drag right there. Don't suppose you have any you want to sell?

Time for plan B

 

[MaxPF]

you cant just "turn solenoids X and Y" on and it will magically go into 6th gear. Thats not the way the allison works (its not a 4L80 or dodge trans ). You will not be able to make 6th gear work without an actual TCM that has 6-speed software in it.

I know how an Allison works. My question was simply what solenoid combos actuate what gears in the 6 speed VB. It was a simple question that didn't require a condescending answer

 

[MaxPF]

Mike, i appreciate you taking the time to talk to me earlier. I now more fully understand the difficulties in getting this whole mess to work

This is gonna be interesting

 

[MaxPF]

So, nobody wants to tell me the solenoid combo that engages 6th gear?

 

[duratothemax]

C and D are off, E is on.

Why do you need to know that? As I said before, you're not gonna get it to shift into 6th gear with a couple toggle switches.

 

[MaxPF]

C and D are off, E is on.

Why do you need to know that? As I said before, you're not gonna get it to shift into 6th gear with a couple toggle switches.

Mainly to satisfy my own curiosity - I only have tech manuals for the 5 speeds at the moment

Hmm, that solenoid combo is the same as 5th on a 5 speed, which means all the combos are likely different Could I ask you to post up all of the solenoid combos for the 6 speed, including P/N and reverse?

 

[cuminstrkmydmax]

Why cant you run a 6 speed TCM-

Steven

 

[THEFERMANATOR]

Why cant you run a 6 speed TCM-

Steven

The 6 speed GEN 4 TCM out of a GM truck uses CAN BUS to get it's info from the ECM to tell it when to shift and such, the 5 speed TCM uses J1939 for this info. There are aftermarket boxes out there that allow you to convert analog sensor outputs over to a J1939 stream so that you can utilize a J1939 compliant device, but as far as I knwo nobody has made one that can work for CAN BUS comms. You COULD use the SUPER rare 8.1L 6 speed TCM from an early 06, but then it would have to be adjusted via EFILIVE for shift points and I believe 5 th is disabled in them at WOT.

 

[duratothemax]

Mainly to satisfy my own curiosity - I only have tech manuals for the 5 speeds at the moment

Hmm, that solenoid combo is the same as 5th on a 5 speed, which means all the combos are likely different Could I ask you to post up all of the solenoid combos for the 6 speed, including P/N and reverse?

1-5 are the same on the 5-speed and 6-speed.

The difference between 5th and 6th gear is that in addition to E-shift being ON, Trim A and Trim B are also both energized in 6th gear. In 5th gear, both trim solenoids are de-energized.

 

[MaxPF]

The 6 speed GEN 4 TCM out of a GM truck uses CAN BUS to get it's info from the ECM to tell it when to shift and such, the 5 speed TCM uses J1939 for this info. There are aftermarket boxes out there that allow you to convert analog sensor outputs over to a J1939 stream so that you can utilize a J1939 compliant device, but as far as I knwo nobody has made one that can work for CAN BUS comms. You COULD use the SUPER rare 8.1L 6 speed TCM from an early 06, but then it would have to be adjusted via EFILIVE for shift points and I believe 5 th is disabled in them at WOT.

Actually, the Gen 4 TCM's use a GMLAN bus, which is a 500kbps variant of CAN but not directly compatible. CAN and J1939 are the same thing, and run at 250kbps.

5 speed boxes are actually easy to run stand-alone. The available modes for throttle input are either TPS, J1939, or autodetect. Basically, any cal that uses TPS or autodetect input can be used in a standalone app. SEM requests can be sent either over the CAN link or via I/O pins on the TCM (8.1 apps use the latter method). SEM can also be disabled using EFI Live, but the torque capability of the transmission is reduced to 550lb-ft according to Allisons documentation. Using the SEM I/O, a driver circuit, and an air solenoid valve, it should be possible to incorporate SEM on a non-electronically controlled engine as long as it has an AFC control on the injector pump. I plan to experiment with this later.

6 speed boxes do have TPS inputs, but I have yet to see an Allison cal that uses it. Since every diesel used electronic injection by the time the Gen 4 controls were introduced it makes sense that nobody ever needed the TPS inputs. So, that means in order to use it, throttle position info, engine speed, torque requests, etc. are sent over the GMLAN bus. If a guy knew what the protocol and information streams looked like it would be possible to interface to it with a slave box like Destroked does with the Gen 3 controller. But, apparently this info is unobtanium, otherwise it wouldn't be a difficult matter to make such a slave box.

As for the super rare 8.1 TCM, I would guess it is the same physical box as the Dmax TCM, but a different cal/OS? Anyway, all the info I has says that from 2003-on the 8.1's got throttle info from the ECM just like the DMax, so how would having the 8.1 TCM help?

 

[MaxPF]

1-5 are the same on the 5-speed and 6-speed.

The difference between 5th and 6th gear is that in addition to E-shift being ON, Trim A and Trim B are also both energized in 6th gear. In 5th gear, both trim solenoids are de-energized.

Thanks Ben, I appreciate the info. However, I am not quite sure I understand how this works. I understand that these are PPC solenoids, and that one controls the oncoming clutch pressure while the other controls the offgoing clutch pressure, and these have to be precisely controlled in order to prevent a flare or lockup. But since that requires both solenoids being energized at some percentage of their max current when solenoid C drops out for the 4-5 shift, it seems to me that an intermediate state of pressure with the trim solenoids would try to apply both C3 AND C4. I could see the C4 clutch being locked out hydraulically unless both solenoids are near max current, but then the question arises as to how they can properly modulate a 5-6 shift

Finally, one last question: Do you know if the 6 speed solenoids operate at the same frequency as the 5 speed solenoids? If not, do you know their operating frequency?

 

[duratothemax]

Actually, the Gen 4 TCM's use a GMLAN bus, which is a 500kbps variant of CAN but not directly compatible. CAN and J1939 are the same thing, and run at 250kbps.

5 speed boxes are actually easy to run stand-alone. The available modes for throttle input are either TPS, J1939, or autodetect. Basically, any cal that uses TPS or autodetect input can be used in a standalone app. SEM requests can be sent either over the CAN link or via I/O pins on the TCM (8.1 apps use the latter method). SEM can also be disabled using EFI Live, but the torque capability of the transmission is reduced to 550lb-ft according to Allisons documentation. Using the SEM I/O, a driver circuit, and an air solenoid valve, it should be possible to incorporate SEM on a non-electronically controlled engine as long as it has an AFC control on the injector pump. I plan to experiment with this later.

You've definitely done your homework on the electronics side. :thumb:

500k HS GMLAN and 250k J1939 are very similar and share some of the same messages, but use different identifiers I believe. If you hook up the GMLAN pins/wires on a Gen 4 GMLAN TCM to an 01-05 Dmax ECM speaking J1939 it will crash the bus and most of the time the truck wont even start.

6 speed boxes do have TPS inputs, but I have yet to see an Allison cal that uses it. Since every diesel used electronic injection by the time the Gen 4 controls were introduced it makes sense that nobody ever needed the TPS inputs.

correct.

So, that means in order to use it, throttle position info, engine speed, torque requests, etc. are sent over the GMLAN bus.

or J1939. If you have the proper cal, the Gen 4 TCM can speak 'old' 250k J1939 instead of 500k GMLAN. Plenty of medium duty 6.7 cummins/6-speed allison applications out there.

The J1939 datalink controller chips in the Gen 4 TCM exist because there are actually different pins for J1939. IE, when the Gen 4 TCM is configured for J1939, it communicates it over different pins on the main 80-pin connector. People I have talked to says the Gen 4 TCM speaks GMLAN and J1939 at the same time, but this doesnt appear to be the case because Ive tried hooking up the J1939 pins on a Gen 4 TCM from a 6-speed dmax to an 01-05 dmax and it wouldnt communicate. However whats strange is the Gen 4 TCM must have been getting some form of TPS data from my 05 dmax ECM because when I drove it around the shift points WOULD INDEED vary with throttle. I dont know if the Gen 4 TCM goes into a default mode and if it doesnt see high speed comms it looks at the Class 2 bus for rudimentary engine info??? I have no idea, but it was definitely getting some form of TPS signal from SOMEWHERE in the truck.

If a guy knew what the protocol and information streams looked like it would be possible to interface to it with a slave box like Destroked does with the Gen 3 controller. But, apparently this info is unobtanium, otherwise it wouldn't be a difficult matter to make such a slave box.

What I want to find out is if the J1939 CAN that the 01-05 dmax ECM speaks is a "garden variety" J1939 CAN, like the same messages and identifiers that any other non-GM J1939 application speaks. Or if the 01-05 dmax J1939 is some weird "GM-ized" form of J1939 CAN.

As for the super rare 8.1 TCM, I would guess it is the same physical box as the Dmax TCM, but a different cal/OS?

correct

Anyway, all the info I has says that from 2003-on the 8.1's got throttle info from the ECM just like the DMax, so how would having the 8.1 TCM help?

nope! Right up until 2007 when the 8.1 left the pickup trucks, the TCM still got TPS info and torque requests over dedicated/discrete PWM wires. The 8.1 ECM physically doesnt have the capability to speak any high speed databus.

Ben

 

[TheBac]

Uh oh, Ben found someone who speaks his language. This could get good.

Ben, I drive a 6.7Cummins/6spd combo at work. Its a Freightliner truck, so maybe get some info from them on cals or hard parts? Want me to ask the mechanics if they can get any info for you? if so, what?

 

[MaxPF]

nope! Right up until 2007 when the 8.1 left the pickup trucks, the TCM still got TPS info and torque requests over dedicated/discrete PWM wires. The 8.1 ECM physically doesnt have the capability to speak any high speed databus.
Ben

So, if the 8.1 gen 4 controller uses TPS input, is there any reason why it wouldn't work stand alone? :dontknow: I assume it still uses an engine speed sensor in the bellhousing?