Allison 545 to Allison 1000 series? possible or not?


New Member
I have a 85 Beaver motorhome with a 427 truck/AT545 combo in it. At 60 MPH it runs at about 3200rpm. Would changing the trans for a 1000 series transmission lower my RPM, give me better hill climbing/dingy towing capibility, better mileage? Would the 1000 series bolt to the 427? What would the ECM requirments be? Thank you for your help!


Senior Member
Re: Allison 545 to Allison 1000 series? possible or not?

It can be done. It is expensive. It would make the vehicle perform much better, if you're willing to invest five grand or more. The hard part is finding a shop that can find the parts and knows how to do the job right.

Replacing an AT in a motorhome, or replacing the transmission in a pickup truck with an Allison are questions that get asked quite often. It's the cost of the job that usually prevents it from getting done. Industrial Automatic Transmission Service (division of Inland Truck Parts) in Irving, TX used to have a deal where they replaced the AT in a motorhome with an MT more cost effectively than putting in the 1000 and you got most of the benefits for a much better price.