TM-9-2520-254-34 Direct Support for M113 TX100-1 Transmission 2520-00-066-4240 Download

(1) A 31-tooth sun gear (38), 59-tooth (in- ternal) ring gear (29), and a planetary carrier assembly (37) with six 14-tooth pinions make up the reverse-range gear set. The sun gear is the driving member, the ring gear is the reaction member, and the carrier assembly is the driven member. (2) The sun gear (38) is splined to reverse- range sun gear shaft (40) which, in turn, is splined to the low-range ring gear (23) which meshes with the low-range carrier pinions. The carrier assembly (37) is splined to the transmission output shaft (33). Its pinions mesh with both the ring gear (29) and sun gear (38). The ring gear (29) has external splines which engage the reverse-range, internal- splined plates. A retainer at the outer circumference of the ring gear (29) prevents the gear moving forward or rearward. c. Operation of Reverse-Range Clutch and Planetary Gears (fig. 2.1). (1) When the reverse-range clutch (28) is applied, the clutch piston (27) compresses the clutch plates against the reaction plate (30). This holds the ring gear (29 ) stationary. The sun gear (38) drives the carrier assembly (37) at a reduced speed but in the same direction as the sun gear (38). To actually obtain reverse rotation which the sun gear and carrier must have, the reverse-range gears are compounded with the low-range gears. (2) Reversing actually takes place in the low- range gear set and its output (ring gear (23)) transmits reverse rotation to the input (sun gear (38) ) of the reverse-range gear set. The overall reverse-rotation speed reduction ratio is 4.35 to 1. (3) When hydraulic pressure is exhausted from the clutch piston housing, springs (43) push the piston (27) back into the housing (26). This permits the reverse-range, internal-splined plates to rotate independently of the stationary, external- tanged clutch plates. 2-6. Oil Pumps a. Components of Front and Rear Oil Pumps (fig. 2-1). (1) The front oil pump (11) includes a pump body, cover. 19-tooth drive gear, and a 22-tooth driven gear. The drive gear has external teeth and the driven gear has internal teeth. Both gears have 6-pitch teeth. (2) The rear oil pump (32) includes a pump body, cover, 26-tooth drive gear, and a 30-tooth driven gear. The drive gear has external teeth and the driven gear has internal teeth. Both gears have 8-pitch teeth. (3) In both oil pumps, the driven gear is mounted eccentrically in mesh with the drive gear. The gears are separated at their unmeshed side by a crescent-shaped partition which is part of the pump body. The width of the front pump gears is more than twice the width of the rear pump gears, giving the front pump greater pumping capacity. b. Operation of Oil Pumps (fig. 2-1). (1) The front oil pump (11) is driven by the torque converter pump hub. It supplies oil to the hydraulic system at any time the vehicle engine is running. Oil is picked up (through the oil filter (55)) from the oil pan (42). (2) The rear oil pump (32) is driven by the reverse-range planetary carrier (37) at any time the vehicle is moving forward. Oil is picked up (through the oil filter (55)) from the oil pan (42). Oil flow produced by the rear pump supplements that of the front pump during vehicle forward operation. It is the only source of oil flow and pressure during push or tow starting. 2-7. Fluid Velocity-Type Governors a. Components of Front and Rear Governors (fig. 2-1). (1) There are two governors in the trans- mission for controlling the automatic functions. The front governor (14) is located at the front of the high-range clutch housing (16). The rear governor (39 ) is located at the rear of the reverse- range planetary (37). (2) Each governor includes a collector ring which rotates with the component to which it is attached, and a pitot tube which is stationary. Each collector ring has a channel around the inside of its rim. There are radial vanes at close intervals in the channel. A port supplies oil to keep the channel filled. When the collector ring is rotating, the channel remains full due to centrifugal force acting to retain the oil. (3) The vanes in the channel keep the oil moving at virtually the same speed as the channel. The pitot tube is a simple tube, stationarily positioned in the oil which fills the channel. The open end of the tube faces against the direction of oil travel. The other end of the tube connects to passages leading to control valves. b. operation of Fluid Velocity-Type Governors (fig. 2-1). (1) The fluid velocity governors (14 and 39) derive their name from the fact that governor pressure is dependent upon the velocity of fluid in the channels of the collector rings. When the collector rings rotate, oil is thrown directly into the open ends of the pitot tubes. (2) The front governor collector ring is welded to the high-range clutch housing and rotates with it. Since the clutch housing is connected to the torque converter turbine by the turbine shaft (59), front governor pressure is proportional to turbine speed. Front governor pressure is called G1 pressure. (3) The rear governor collector ring is riveted 2-5