Allison 2500 Upgrade Options

[mangus580]

I am looking at upgrade options for the crappy AT545 in my 97 International/Bluebird bus. I have the T444e engine.

Locally I have found 2 different Allison 2500 transmissions, but both have come from the 8.1 gas engine in one of the GM 5500 truck. I can get them complete with wiring and TCU, and appear to be a direct bolt up to the SAE setup the T444 uses.

What I am wondering is can I (and where) get the TCU updated to work properly with my engine?

 

[nikitis]

Some items of information you may be missing.

The T444E is SAE2 by default, but most of these on Buses come with a SAE2 to SAE3 Ring converter which also adds length to the whole process.

You may require a new flywheel and potentially torque converter as well to make it fit directly and work.

I've not seen anyone really try to just bolt directly SAE2, but Cadillackid who knows these pretty well stated that it may need a new flywheel if you attempted this. So something to consider.

Another item which makes this difficult is that your 97 ECM is J1708 protocol, and a AT2500 expects a J1939 protocol. So your TCM will not work directly with your bus.

I know the struggle, as I'm in the same boat.

To fix this protocol issue, you need an AU device which can translate what the transmission needs from J1708 to J1939. This is needed so the live RPM data can be sent to the TCM on the transmission to know when to shift gears.

Another problem is even if you wire in this J1708 to J1939 AU device, now you have a throttle position issue. You have to get a specially made throttle controller added so it can show you the position of your throttle because the ECM won't communicate this accurately to your TCM. CAC Customs makes this device. Google it.

Additionally 2500's from small consumer trucks don't fit unless they are labeled as SAE2 or 3, if it's from a large medium duty haul truck it will.

We talk extensively about this replacement process here:
Adding J1939 to a 3Box Bus.

I provide a wiring diagram to make it work, and the Bouje guy on there actually took this diagram and ran with it without us actually testing it lol, but he reported back that it did work for him.

Also I would consider getting instaed of a 2500 Allinson, get a AT1000 with 6 speeds and 2 lock up gears from the years 2006-2009. It's likely the best replacement for your setup with best ratios.

 

[ewo1]

I am looking at upgrade options for the crappy AT545 in my 97 International/Bluebird bus. I have the T444e engine.

Locally I have found 2 different Allison 2500 transmissions, but both have come from the 8.1 gas engine in one of the GM 5500 truck. I can get them complete with wiring and TCU, and appear to be a direct bolt up to the SAE setup the T444 uses.

What I am wondering is can I (and where) get the TCU updated to work properly with my engine?

There is a boat load of busses being sold today dirt cheap, great place to find yourself a donor bus and get all the parts in one place!

Public Surplus: Browse all categories

www.publicsurplus.com

 

[mangus580]

Some items of information you may be missing.

The T444E is SAE2 by default, but most of these on Buses come with a SAE2 to SAE3 Ring converter which also adds length to the whole process.

You may require a new flywheel and potentially torque converter as well to make it fit directly and work.

I've not seen anyone really try to just bolt directly SAE2, but Cadillackid who knows these pretty well stated that it may need a new flywheel if you attempted this. So something to consider.

Another item which makes this difficult is that your 97 ECM is J1708 protocol, and a AT2500 expects a J1939 protocol. So your TCM will not work directly with your bus.

I know the struggle, as I'm in the same boat.

To fix this protocol issue, you need an AU device which can translate what the transmission needs from J1708 to J1939. This is needed so the live RPM data can be sent to the TCM on the transmission to know when to shift gears.

Another problem is even if you wire in this J1708 to J1939 AU device, now you have a throttle position issue. You have to get a specially made throttle controller added so it can show you the position of your throttle because the ECM won't communicate this accurately to your TCM. CAC Customs makes this device. Google it.

Additionally 2500's from small consumer trucks don't fit unless they are labeled as SAE2 or 3, if it's from a large medium duty haul truck it will.

We talk extensively about this replacement process here:
Adding J1939 to a 3Box Bus.

I provide a wiring diagram to make it work, and the Bouje guy on there actually took this diagram and ran with it without us actually testing it lol, but he reported back that it did work for him.

Also I would consider getting instaed of a 2500 Allinson, get a AT1000 with 6 speeds and 2 lock up gears from the years 2006-2009. It's likely the best replacement for your setup with best ratios.

Much of this I knew, as I have been following along. Granted, I did not know about the throttle position issue.

Arent the AT1000 6 speeds more difficult to find with the SAE2/3 bellhousing vs the standard 'SBC' bell housing?

I am mostly looking to 'upgrade' as the bus is a turd to drive with the 175hp T444e and the AT545 behind it..... LOL Some day I will figure out how to bump the 175 up to 210 or so.... Still trying to find the Godmode version of ServiceMaxx to do this...

 

[Timeline]

I miss cadillackid he would know...

What I am wondering is can I (and where) get the TCU updated to work properly with my engine?

I'm wondering if you could get some help with that by contacting a nearby school bus garage.
Hope you get it figured out!
John

 

[mangus580]

What happened to cadillackid?

 

[Timeline]

Haven't seen him here in a while, is all. Hope all is well with him.

 

[Kentucky Dreaming]

I am looking at upgrade options for the crappy AT545 in my 97 International/Bluebird bus. I have the T444e engine.

Locally I have found 2 different Allison 2500 transmissions, but both have come from the 8.1 gas engine in one of the GM 5500 truck.

You might want to research the gear ratios in a tranny from behind a gasser as compared to a tranny made to go behind a diesel. Gassers run at higher RPM than diesels.

 

[nikitis]

I just sent him a text, we'll see what's up.

Arent the AT1000 6 speeds more difficult to find with the SAE2/3 bellhousing vs the standard 'SBC' bell housing?

I am mostly looking to 'upgrade' as the bus is a turd to drive with the 175hp T444e and the AT545 behind it..... LOL Some day I will figure out how to bump the 175 up to 210 or so.... Still trying to find the Godmode version of ServiceMaxx to do this...

Actually there's plenty of SAE3 Bell housing for the AT1000, and I don't think you need a flywheel upgrade with it. In some cases you may need a drive shaft length adjustment, depending on your bus. Getting the TCM working with J1708 and Throttle position device is still required but will be the case with any transmission.

Don't let the low number in AT1000 fool you. The 1000 is a beast of a trans.

 

[nikitis]

Cadillackid replied to me. He's doing well. He's had some life changes and busy, but will likely be back soon.

 

[Gorzie]

Much of this I knew, as I have been following along. Granted, I did not know about the throttle position issue.

Arent the AT1000 6 speeds more difficult to find with the SAE2/3 bellhousing vs the standard 'SBC' bell housing?

I am mostly looking to 'upgrade' as the bus is a turd to drive with the 175hp T444e and the AT545 behind it..... LOL Some day I will figure out how to bump the 175 up to 210 or so.... Still trying to find the Godmode version of ServiceMaxx to do this...

I was hoping to use ServiceMaxx to bump up my HP also but I found out you need to have a "3 box" system. I didn't know what this was at first. If it is a 3 box system it will have some of the computer parts on the passenger side of the engine. My bus is a mid 1997 build and doesn't have this so no easy computer upgrade.

 

[mangus580]

I was hoping to use ServiceMaxx to bump up my HP also but I found out you need to have a "3 box" system. I didn't know what this was at first. If it is a 3 box system it will have some of the computer parts on the passenger side of the engine. My bus is a mid 1997 build and doesn't have this so no easy computer upgrade.

I have the 3 box.... just cant find the right software :-(

 

[nikitis]

I was hoping to use ServiceMaxx to bump up my HP also but I found out you need to have a "3 box" system. I didn't know what this was at first. If it is a 3 box system it will have some of the computer parts on the passenger side of the engine. My bus is a mid 1997 build and doesn't have this so no easy computer upgrade.

You can use Servicemaxx on newer than 1997. You cannot modify the HP on Servicemaxx without a dealer account. Dealers lock it down so they can charge you money to modify. There are some people who can do it for you but you won't find the software likely out in the wild. It's locked down, and not exactly legal to distribute the accounts if you have one.

Open your hood and take a picture of the upper firewall on the drivers side.

A 3 box has it set up this way in every model.

If it's a 1 box, you only have a single computer mounted on the top of the engine on the passenger side. It's a silver box looks like it's floating in air almost. If that is missing and looks like mine, it's a 3box.

The IDM (i don't have a good picture), but an arrow below points to the edge, and is in the engine compartment on the firewall with 3 relays mounted and the map sensor, not under the dash like the ECM and VPM.

The VPM isn't meant to be accessible at all. I cut a hole in my firewall because I had to replace mine as it was dead. Pray this never happens to you. The ECM input is accessible under the listed cover below from the engine bay on the firewall and is accessible. To remove the ECM it's difficult as it's tucked up tight under the dash from inside the drivers side dash.

Let us know what you have. Pictures would be good to for identifying similar locations as mine, but also take one of your passenger side engine and we can confirm for you.

 

[mangus580]

Isnt it a special version of Servicemaxx?

 

[magnakansas]

The 2000 series Allison transmission can be found with sae #2 housings. Most are sae #3 housings. If you have a 545, that should be sae#3 housing. I have never seen a 545 with a #2 housing. As far as I know, all 3000 series Allison and 643 and 653 are sae#2 housings.

William

 

[nikitis]

Isnt it a special version of Servicemaxx?

It's a different version but the origianl version. Servicemaxx J1708 is free for older J1708 vehicles and a few changes can be made for free, but not all. Godmdoe Servicemaxx supports J1939 as well and it's an illegal account included that was leaked but blacklisted that works locally in the software but not if the software connects to the internet, and then it enables an administrator edit mode in the software which allows values to be edited and written to your ECM. People say it's a special version to simplify it for the non-technical. Distribution of the account is not legal. Servicemaxx works through the Duramaxx year engines as well into the early 2000's After that you need NavCal which is online only and Dealer only. They corrected their oversite from ServiceMaxx being able to run locally without internet with a leaked account.

The 2000 series Allison transmission can be found with sae #2 housings. Most are sae #3 housings. If you have a 545, that should be sae#3 housing. I have never seen a 545 with a #2 housing. As far as I know, all 3000 series Allison and 643 and 653 are sae#2 housings.

William

T444E's with AT545's are actually SAE #2 housings with a SAE #3 adapter ring so the AT545 which is SAE #3 will fit to the T444E.

The T444E itself is SAE #2. If you had an SAE #2 transmission though, I'm not sure you could just bolt it on without the adapter. You may still need to change the flywheel and possibly a different torque converter because without the adapter spacing ring, you'd be bolting it 1-2 inches closer to the Engine so I'm not 100% on how that would all fit or if there is enough room. That is the only question.

 

[mangus580]

It's a different version but the origianl version. Servicemaxx J1708 is free for older J1708 vehicles and a few changes can be made for free, but not all. Godmdoe Servicemaxx supports J1939 as well and it's an illegal account included that was leaked but blacklisted that works locally in the software but not if the software connects to the internet, and then it enables an administrator edit mode in the software which allows values to be edited and written to your ECM. People say it's a special version to simplify it for the non-technical. Distribution of the account is not legal. Servicemaxx works through the Duramaxx year engines as well into the early 2000's After that you need NavCal which is online only and Dealer only. They corrected their oversite from ServiceMaxx being able to run locally without internet with a leaked account.

Any idea where it could be located? I had one person offer it to me, but he hasnt followed through...

 

[Gorzie]

You can use Servicemaxx on newer than 1997. You cannot modify the HP on Servicemaxx without a dealer account. Dealers lock it down so they can charge you money to modify. There are some people who can do it for you but you won't find the software likely out in the wild. It's locked down, and not exactly legal to distribute the accounts if you have one.

Open your hood and take a picture of the upper firewall on the drivers side.

A 3 box has it set up this way in every model.

If it's a 1 box, you only have a single computer mounted on the top of the engine on the passenger side. It's a silver box looks like it's floating in air almost. If that is missing and looks like mine, it's a 3box.

The IDM (i don't have a good picture), but an arrow below points to the edge, and is in the engine compartment on the firewall with 3 relays mounted and the map sensor, not under the dash like the ECM and VPM.

The VPM isn't meant to be accessible at all. I cut a hole in my firewall because I had to replace mine as it was dead. Pray this never happens to you. The ECM input is accessible under the listed cover below from the engine bay on the firewall and is accessible. To remove the ECM it's difficult as it's tucked up tight under the dash from inside the drivers side dash.

Let us know what you have. Pictures would be good to for identifying similar locations as mine, but also take one of your passenger side engine and we can confirm for you.

I guess I had it backwards. I thought the one with the computer by the passenger side valve cover was a 3 box system. So do I have a 3 box system? I hope so. I would like to bump up my HP once I know my engine is in shape and can handle it. It is currently marked as 175HP but my scan gageD only shows i get 160hp max

 

[nikitis]

Yup, you're a 3 Boxer. Welcome to the club! We're a rarer breed these days.

As long as your computers work it's not a terrible system, but digital options like bluefires won't provided you a ton of info, but you can get the basic stuff like speed and RPM's if you ever wanted to upgrade your dash to a digital dash. J1939, or 1 boxes can get a lot more digital information so on a 3box it's only really worth a bluefire in most opinions if your gauge cluster is missing so I wouldn't waste the money on one for that bus.

The benefit of 3 Box buses with Thomas bodies are very strong bodies that don't seem to rust as easily. Even buses 10 years old tend to rust faster due to the metal they use. Our 30 year old buses are often in better shape body wise, have better rivets used and simply look great! Our buses engine components are easier to work on too. No body control modules or multiplexing going on. Just straight wire tracing.

If the VPM (1 of 3 boxes) ever dies you won't be stranded, you can still drive but you'll be speed limited.
If the IDM (Injector driver module, 2 of 3 boxes) dies or the ECM (3 of 3 boxes) dies, you'll be stranded, but on a 1 box bus if it dies, you are just stranded, we get at least a 1 in 3 chance of not being stranded

The downside is these are the first computers put into buses so they are OLD, and prone to die eventually. There are still replacements you can scrounge from dead buses but they are getting harder and harder to find as time goes on so most avoid for this reason. There are no "New" VPM, ECM's or IDM's from International. Any replacement computer you get will be a used one, and may require a reprogramming from NavCAL to get the replacement computer in sync with the other 2 computers. Not a DIY replacement job in every case. Sometimes you can get lucky with a replacement computer and it's compatible with the other two computers and work fine but with incorrect info like VIN and Mileage etc.

Your bus body will be some of the best built by Thomas in the last 30 years though.

 

[Gorzie]

Well that's good to hear. I now just need to get the "good" of servicemax that allows me to change the setting. I have a bluebird body and it has a couple of small rust spots I am going to repair this summer. Thanks for the information. I could never figure out it 1997 builds started with or ended with the 3 box.