Allison 2500PTS 6th Gear Unlock

[Pizote]

I got to talking to an Allison dealer about unlocking 6th gear on a 2500PTS.

While it can be done, the process is bureaucratic and not guaranteed. There are two paths you can take:

1. Allison and OEM of bus authorization
2. PCM Performance (pcmperformance.com)

Before you start, any Allison 2500PTS manufactured AFTER June 28, 2006 is capable of taking advantage of the TCM being unlocked. Transmissions manufactures prior to this have hardware differences and must be altered (no guarantee) to work with the TCM flash. Each transmission has a date code. It follows this format YYMDD.

1. Where

2. YY is the last two digits of the year (06 for 2006)
3. M is a letter that translates to the month (A is Jan, J is October)
4. DD is the day of the month

Unfortunately, my date code os 06D28 - and manufactured prior to June 28, 2006 so mine is not able to take advantage of the TCM flash.

So here we go:

• For an authorized Allison dealer, follow the instructions in the PDF attachment.
• To go outside of the Allison authorization, go to PCM Performance - Alex will charge you ~$300-350 to flash your TCM or you can purchase a new one from him for $500.

Here's the mythical Allison instructions: http://www.pizoteadventures.com/down...ashRequest.pdf

[o1marc]

Most of us own older buses. I don't know what the year cut off is, but Allison regularly says "it's too old" to authorize unlocking. PCM says they don't have the hardware or software to do the early models, mine is a 99 and they wouldn't do it. Seems like the only out is to buy a computer that already has the 6th unlocked.

[Pizote]

Originally Posted by o1marc

Most of us own older buses. I don't know what the year cut off is, but Allison regularly says "it's too old" to authorize unlocking. PCM says they don't have the hardware or software to do the early models, mine is a 99 and they wouldn't do it. Seems like the only out is to buy a computer that already has the 6th unlocked.

The issue is that while the TCM I have can be reflashed, the transmission does not have the hardware required. As stated, the cutoff is June 28th 2006. Any 2500PTS manufactured before that date will not work.

[Booyah45828]

That's correct. The difference is in the valvebody/solenoid pack.

I know on the 1000's you can drop the pan, swap the parts, upgrade the tcm, and have 6th. I've done it and it worked well. But I'm not sure on the others. I know they're similar to the 1000 but how similar is the question.

[Sp6saz]

Originally Posted by Booyah45828

That's correct. The difference is in the valvebody/solenoid pack.

I know on the 1000's you can drop the pan, swap the parts, upgrade the tcm, and have 6th. I've done it and it worked well. But I'm not sure on the others. I know they're similar to the 1000 but how similar is the question.

Pts is that push button trans. I have a shift lever t handle style my transmission is Allison 2500 MH transmission. Anyone know if this transmission of mine has a 6th gear that can be unlocked

[musigenesis]

Originally Posted by Sp6saz

Pts is that push button trans. I have a shift lever t handle style my transmission is Allison 2500 MH transmission. Anyone know if this transmission of mine has a 6th gear that can be unlocked

What year is it?

[Sp6saz]

Originally Posted by musigenesis

What year is it?

It is a 2006 international ce 300 bus the engine is a 2006 dt466e the tranny is a 2500 HD

[musigenesis]

Originally Posted by Sp6saz

It is a 2006 international ce 300 bus the engine is a 2006 dt466e the tranny is a 2500 HD

Hmm, I believe that's the year the 2000-series started having 6th gear able to be unlocked just in software, so yours may or may not be that. Others here may know for sure.

[Sp6saz]

Originally Posted by musigenesis

Hmm, I believe that's the year the 2000-series started having 6th gear able to be unlocked just in software, so yours may or may not be that. Others here may know for sure.

That would be great well I think it would who would have this software

[cadillackid]

you need a 4th gen TCM in your allison to get 6th..



PTS simply means Pupil Transport System.. essentially the trans program is programmed for school bus usage



if you find your TCM and it has one large 80 pin connector on it then its a 4th gen, if it has 2 connectors its a 3rd gen.


2006 is the transition year.. most bus chassis are a year behind.. but the easiest way is just to look for the TCM..

[Sp6saz]

Originally Posted by cadillackid

you need a 4th gen TCM in your allison to get 6th..



PTS simply means Pupil Transport System.. essentially the trans program is programmed for school bus usage



if you find your TCM and it has one large 80 pin connector on it then its a 4th gen, if it has 2 connectors its a 3rd gen.


2006 is the transition year.. most bus chassis are a year behind.. but the easiest way is just to look for the TCM..

Thank you, I'm guessing the tcm will be on our near the tranny. I have high hopes now as the bus is a 2007 but the engine is a 2006 here's to hoping that I have 180 pin connector. Thank YOU and everyone for all the help here. I'm not unhappy with my engine or tranny performance but heating that this might improve mileage and decrease cabin noise of course I'm interested if it's reasonably attainable otherwise I'll take what I got and like it.

[cadillackid]

if you are looking to increase road speed then driveshaft RPMs become a concern.. at an engine max RPM of 2600 you wont reach the 4000 that allison says is maximum driveshaft RPM for most of their transmissions (recommended).. but you can pickup some driveline noise esp if the driveshaft set isnt perfectly phased and balanced..



if you are just looking to droip engine RPM then your driveshaft speed wont change at all..

[Sp6saz]

Originally Posted by cadillackid

if you are looking to increase road speed then driveshaft RPMs become a concern.. at an engine max RPM of 2600 you wont reach the 4000 that allison says is maximum driveshaft RPM for most of their transmissions (recommended).. but you can pickup some driveline noise esp if the driveshaft set isnt perfectly phased and balanced..



if you are just looking to droip engine RPM then your driveshaft speed wont change at all..

I've had the bus going as fast a 80 mph but not for a long period of time and I did not take note of the engine rpm I usually do 64mph as it just seems like it wants to run there and it's at 2200 rpm I just figured less rpms and better fuel mileage would be nice. I checked my transmission electrical connector to the tcm at least i think it was the tcm and it looks like two wire looms go to one large connector with a bolt in the middle of the connector it just looks like one big connector though even though there's two bundles of wires going to it one bundle on each side of the retaining bolt. Maybe I'll get lucky and I can have 6'th gear turned on that'd be cool.

[Sp6saz]

Originally Posted by Pizote

I got to talking to an Allison dealer about unlocking 6th gear on a 2500PTS.

While it can be done, the process is bureaucratic and not guaranteed. There are two paths you can take:

1. Allison and OEM of bus authorization
2. PCM Performance (pcmperformance.com)

Before you start, any Allison 2500PTS manufactured AFTER June 28, 2006 is capable of taking advantage of the TCM being unlocked. Transmissions manufactures prior to this have hardware differences and must be altered (no guarantee) to work with the TCM flash. Each transmission has a date code. It follows this format YYMDD.

1. Where

2. YY is the last two digits of the year (06 for 2006)
3. M is a letter that translates to the month (A is Jan, J is October)
4. DD is the day of the month

Unfortunately, my date code os 06D28 - and manufactured prior to June 28, 2006 so mine is not able to take advantage of the TCM flash.

So here we go:

• For an authorized Allison dealer, follow the instructions in the PDF attachment.
• To go outside of the Allison authorization, go to PCM Performance - Alex will charge you ~$300-350 to flash your TCM or you can purchase a new one from him for $500.

Here's the mythical Allison instructions: http://www.pizoteadventures.com/down...ashRequest.pdf

So where can I find this date code for the transmission

[Sp6saz]

So I saw a you tube video shows a guy putting in a new valve body and new tcm from after market place in his 2500 Allison why couldn't someone do that to a bus with the same transmission

[musigenesis]

Originally Posted by Sp6saz

So I saw a you tube video shows a guy putting in a new valve body and new tcm from after market place in his 2500 Allison why couldn't someone do that to a bus with the same transmission

That is what they do if it's too old to be unlocked just with software. That's obviously more work, though.

[cadillackid]

you can do that.. the kit is a couple grand.. so you can gain from a 0.74 OD (5th) to 0.64 (6th).. its a couple hundred RPM in most cases.. nice to have but not a necessity unless you are running against the rev limiter..



I put 6th in mine because I was starting from scratch and I wanted brand new performance built trans and all the bits where I could "build to suit" so it made sense to put in a 6 speed.. (somehow I knew.. even though I said not.. that my bus would end up "built" with 'slightly more Horsepower than it had stock'......)



if the trans is already a 4th gen ready for 6th then getting a 3rd party to do it is prob the best way.. the dealer wont want to do it.. the paperwork is horrendous...