The 105 Tractairs have rounded inner corners on the top sheet metal, and the compressor control valve sticks through the side panel. the 125s have square corners with the lever in the open. Most 125's have an air aftercooler in front of the radiator. Most Tractairs have the LeRoi D226 egine (4 bore x4 1/2 stroke), although I think some early LeRoi/late Centaur units may have used the D176 or D201 engines. There are differences in air tanks and manifolds but I don't have specific model #'s to determine the changes.





The following are some part numbers for various LeRoi engines. Thanks to Larry Evans for send me these.

Federal Mogul part numbers for LeRoi D226 (1993 catalog)
Federal Mogul part numbers for LeRoi D176 (1993 catalog)
Clevite (TRW) part numbers for LeRoi page 1 (1984 catalog)
Clevite (TRW) part numbers for LeRoi page 2 (1984 catalog)




Here are some general specifications from a 1963 Tractair operation and maintenence manual.

page one 125 Tractair engine specs
page two 125 Tractair engine specs


Lube chart for 125 Tractair engine
Lube chart for 125 Tractair chassis


Control chart for 125 Tractair
driver view of a 125 Tractair