8.3 Cummins, What Allison tranny?

[kenny76]

I have located a potential bus or 4 that are a bit on the higher side price wise but I have specific wants. I love the West Coast and the MT, WY areas of the country. That said a lock up transmission is an absolute must, as is air brakes in my opinion. Can anyone tell me if the non lock up AT545 was commonly used on the buses with the 8.3 cummins motor. There are tons of 3126's out there but I am staying away because of know fuel delivery system issues and the whole disposable motor issue.

[White99z]

The majority of the 8.3 cummins I have seen lately have an MT643 behind them. I don't have a ton of experience though, so I will let others chime in!

[Stu & Filo. T]

My 1988 Crown with the 8.3 has the Allison 647 Auto

[JakeC]

I don't think any 8.3 came with an AT545. For starters, they wouldn't even be able to handle the rated torque of most 8.3's.

[opus]

It would be a 643 unless it was newer than maybe 97. Then it might be a 3060. 545's werent used on 8.3's.

[nat_ster]

Originally Posted by JakeC

I don't think any 8.3 came with an AT545. For starters, they wouldn't even be able to handle the rated torque of most 8.3's.

Jake and Opus are right.

No 8.3 ever had a at545 behind it due to the lowest tuning of the 8.3 being 40% over the maximum allowable input of the 545.

Nat