Multifuel Automatic Transmisson?

tobyS said:

Hope you work this out Rusty. The 545 is a well regarded transmission but a 5-6 speed would be really nice. Good luck.

Don't forget to get one with the PTO ring if you want a tranny mounted PTO. From what I can tell, the PTO gear is optional on the 545 while all of the 1545 have them. The same PTO as the 939 series fits but it has to be a direct mount pump, no room for driveshaft. Kits for the flange mount do fit the PTO (from the 939 series) and many different pump input shafts can be accommodated. I have a surplus one with a 1"-15 spline (going to smaller pressure comp pump on mine).

Click to expand...

I do know about the PTO ring. Also you could have a "retarder" installed there if you ordered it that way. Or you could rebuild it and install either the PTO ring or retarder. I would go with the PTO ring myself. I have a couple of transmissions I'm looking at right now. Both already have PTO's installed. I just need that flex plate.

A few years back I had a spare Allison RDS2500 with the computer and it had an SAE3 bell housing. I had a few people help me figure a way to install it in an A2. After a few months of parts searching and planning I left the project to die on the drawing board. It wasn’t financially viable. I was at just over $8000.00 counting the transmission cost to get it installed and running correctly. So my A2 still has a manual trans and I bought an A3 so I could have an automatic.

shannondeese said:

A few years back I had a spare Allison RDS2500 with the computer and it had an SAE3 bell housing. I had a few people help me figure a way to install it in an A2. After a few months of parts searching and planning I left the project to die on the drawing board. It wasn’t financially viable. I was at just over $8000.00 counting the transmission cost to get it installed and running correctly. So my A2 still has a manual trans and I bought an A3 so I could have an automatic.

Click to expand...

What did you do with the Allison? Enjoy the A3....I'm in process of making mine 4x4.

shannondeese said:

A few years back I had a spare Allison RDS2500 with the computer and it had an SAE3 bell housing. I had a few people help me figure a way to install it in an A2. After a few months of parts searching and planning I left the project to die on the drawing board. It wasn’t financially viable. I was at just over $8000.00 counting the transmission cost to get it installed and running correctly. So my A2 still has a manual trans and I bought an A3 so I could have an automatic.

Click to expand...

Personally I would stay away from any transmission with a computer for a Multi-fuel engine. All the needed inputs and sensors would just be a pain in the butt. I have a M600 series sitting outside right now, though I will probably go with the AT540. Smaller and easier to install. Though if I come across an old six speed "MT42" series I would go with that. I rebuilt those at "Neils Detroit Diesel" in Phoenix AZ back in the day. Good units. Heavy ! but good.

I think there is one Alison 6 speed model that is not electronic. I believe it came in some busses. I read sometime back that there were controllers for the electronic trans available also, but didn't look into it further.

Greg, is the M42 a manual trans 6 speed? Is there an overdrive or is final drive 1/1?

A combination that I have thought about is the 809 series truck and Spicer 5 speed (or go to automatic from 939 series) with the transfer case from a M939 series.

tobyS said:

I think there is one Alison 6 speed model that is not electronic. I believe it came in some busses. I read sometime back that there were controllers for the electronic trans available also, but didn't look into it further.

Greg, is the M42 a manual trans 6 speed? Is there an overdrive or is final drive 1/1?

A combination that I have thought about is the 809 series truck and Spicer 5 speed (or go to automatic from 939 series) with the transfer case from a M939 series.

Click to expand...

All the Allison's that were "mechanically shifted" had 1:1 in final drive. It is the "electronically shifted" units that have overdrives. The old MT30/41/42 series transmissions where all cast-iron and used in everything from buses to dump trucks. They were extremely hardy units but their weight killed them. Once the aluminum Allison's came out for highway use in the early 1970's all the manufactures wanted them for the extra fuel economy and added weight carrying ability of their trucks.
I installed one in a 1974 Chevy C60 truck once. It was a pesticide spraying rig and carried a 600 gallon tank and PTO spray pump. It had an SM464 four speed in it originally with a two speed differential . The added two gears really helped move that truck ! Plus they all came with a built in "Retarder" so it helped the brakes last longer. The two speed differential still worked great behind that automatic too.

I see I missed read your last post. The MT series Allison transmission's are all automatics.

I dropped it in an HMMWV behind a Cummins 5.9.

shannondeese said:

I dropped it in an HMMWV behind a Cummins 5.9.

Click to expand...

Are you saying you installed a Allison MT42 series behind a Cummins 5.9 engine ? How did it work out ?