Operation Manual for Mack DM and DMM model trucks. Chapters cover Unit ID, Break-In, Instruments and Controls, Brake Operation, Cab Heater and Controls, Cooling System, Operating Instructions, Transmissions, Steering, Tires, Wheels and Rims. Professionally reprinted, revised edition, highly illustrated with numerous pictures, charts and tables, 44 pages.This manual was first published in 7/66 but several revisions are also listed on the inside last page as follows: 9/69; 8/71; 10/72; 6/73; 3/74; 11/75; and 12/76. Although the manual is not actually dated, one can safely assume that this version covers all of those revisions. I also note that the transmission section has detailed instructions on shifting both 2-stick and Maxitorque transmissions. In fact, the picture of the cab detail shows a two-stick transmission. The following models are also listed: DM487, 492, 607, 609, 611, 612, 685, 686, 867, 885, 886, 895, 897 and DMM6116, 6856 and 6866.