TM-9-2520-234-35 Technical Manual for M109 Transmission XTG-411-2A Download

PAR 13-14 DESCRIPTION AND OPERATION OF CHAP 2, SEC II MAIN TRANSMISSION ASSEMBLY 45, four external-tanged 46 plates, piston 50, springs 49 and retainer 48. Housing 55, in which piston 50 operates, serves both the low- and reverse-range clutches. Low-range planetary ring gear 38 serves as the hub of the clutch. (2) Clutch housing 44 is anchored to the transmission housing by anchor bolt 43. External tangs on plates 46 engage slots in housing 44. Internal splines on plates 45 engage external splines on ring gear 38. Piston housing 55 is anchored to the transmission housing by bolt 42 (fig. 375, fold-out 4). Spring retainer 48 (fig. 376, fold-out 5) and springs 49 push the piston into housing 55 when the clutch is released. b. Low-range Planetary Gearing Components (fig. 376, fold-out 5) (1) The low-range planetary gear- ing includes a 60-tooth ring gear 38, four 20-tooth pinions 30, a 20-tooth sun gear 62 (fig. 375, fold-out 4), four spindles 34 (fig. 376, fold-out 5) and shaft and carrier assembly 27. The pinions rotate on needle bearing rollers 31 on the spindles mounted in the carrier. (2) Low-range ring gear 38 is splined to intermediate-range carrier as- sembly 16 and retained by retaining ring 15. Sun gear 62 (fig. 375, fold-out 4) is splined to turbine shaft 2 and retained by retaining ring 63. The transmission range output shaft is an integral part of carrier 27 (fig. 376, fold-out 5). The carrier is supported by reverse-range carrier assem- bly 6 (fig. 377, fold-out 6) and the output transfer drive gear. c. Operation of Low-range Clutch and Planetary Gearing (fig. 376, fold-out 5) (1) When hydraulic pressure is directed to the cavity between piston 50 and housing 55, the piston moves against clutch plates 45 and 46. This compresses the plates against clutch housing 44 and locks the clutch plates together. Ring gear 38 is thus prevented from rotating and becomes the reaction member of the planetary gear set. (2) Sun gear 62 (fig. 375, fold-out 4), driven by the turbine shaft, imparts rotation to pinions 30 (fig. 376, fold-out 5). The pinions, in mesh with the internal teeth of ring gear 38, are forced to rotate within the stationary ring gear. This action causes low-range planetary shaft and car- rier 27 to rotate. The speed reduction ratio is 4 to 1. (3) When hydraulic pressure is released from the piston, springs 49 push the piston into housing 55. This allows the clutch plates to separate and rotate freely, releasing the clutch. 14. REVERSE-RANGE CLUTCH AND PLANETARY GEARING a. Reverse-range Clutch Components (fig. 377, fold-out 6) (1) The reverse-range clutch includes support 18, four plates 1 and 3, four plates 2 and 5, piston 60 (fig. 376, fold-out 5), springs 61 and retainer 62. These parts, except support 18 (fig. 377, fold-out 6) are identical to the 10 low-range clutch components. Housing 55 (fig. 376, fold-out 5) serves the low- and reverse- range clutches jointly. (2) Support 18 (fig. 377, fold-out 6) is anchored, by integral lugs, in slots in the rear transmission housing to prevent rotation. Two screws 19 position it tem- porarily during assembly. External splines on ring gear assembly 4 serve as the clutch hub. b. Reverse-range Planetary Gearing Components (fig. 377, fold-out 6) (1) The reverse-range planetary gearing includes a 75-tooth ring gear assembly 4, six 18-tooth pinions 14, a 39- tooth sun gear 39 (fig. 376, fold-out 5), six spindles 7 (fig. 377, fold-out 6) and a car- rier 17. The pinions rotate on needle hearing rollers on the spindles which are mounted in the carrier. (2) Sun gear 39 (fig. 376, fold-out 5) is splined to low-range ring gear 38 and retained by retaining ring 40. Carrier 17 Change 2 15