TM 9-2520-246-34 CHAPTER 3 REPAIR OF TRANSMISSIONS Section I. DESCRIPTION, OPERATION, AND DATA (MODEL 3052) 3-1. General. This chapter contains the repair instructions for transmission models 3052 and 3053A. This section provides the description, operation, and data pertinent to the five-speed synchromesh, manually shifted transmission model 3052. 3-2. Description. a. General. Transmission model 3052, shown in figure 3-1, is utilized on the 2½-ton, 6x6, M44 series vehicles using a gas engine, not equipped with a front winch. This same transmission is used with vehicles equipped with a front winch. The transmission has a power takeoff mounted on the left side (fig. 3-2) which is used to drive the winch. The construction of the transmission is illustrated in figures 3-3 to 3-11. b. Operation. (1) Power Flow. The flow of power through the transmission gear train and shafts is graphically shown in figure 3-12. In operation, the input gear is constantly applying power to the countershaft, regardless of the speed selected by the operator, because the input gear and countershaft drive gear are continuously meshed. Because the countershaft gears are integral with, or keyed to, the countershaft, power is continuously available at any countershaft gear. Due to the constant mesh of second, third, and fifth (overdrive) gears of the mainshaft and countershaft, locking any one of these gears to the mainshaft causes the mainshaft to rotate at a rate proportionate to the ratio of that gear to the countershaft gear with which it is meshed. Rotation of the mainshaft is in the same direction as that of the input shaft, except in reverse gear. (2) Reverse Gear Power Flow. Power is transmitted by the countershaft second-speed reverse- idler gear and the constantly meshed reverse-idler gear to the mainshaft first-speed reverse gear, which is splined to the mainshaft, driving the mainshaft in the direction opposite to the input shaft. (See fig. 3-12, view A.) (3) First Speed Power Flow. Power is transmitted by the countershaft and mainshaft first-speed gears to the mainshaft. (See fig. 3-12, view B.) Figure 3-1. Transmission Models 3052 and 3053A - Exterior Components. 3-1