Output Drive Clutches, Left and Right

TM 9-2520-249-34&P

faster or forward-moving track. Cross shaft rotation is

reverse clutch is engaged at the opposite side.

transmitted to the output shaft at a 1 to 1 ratio.

(3) The steer clutches also are used, in

first gear only, as drive clutches during straight travel.

For this travel condition, both steer clutches are

2-17.

Output Reduction Gears, left and Right

applied.

a. Description.

NOTE

2-16.

Output Drive Clutches, Left and Right

The left set of output transfer gears (FO-7) and

a. Description.

the right set of output transfer gears (FO-8) are

NOTE

identical. Therefore, the description of one set

The left output clutch (FO-7) and the right

will serve to describe the other.

The

output clutch (FO-8) are identical. Therefore,

description below is keyed to foldout 7, left

the description of one clutch will serve to

output reduction gears.

describe the other. The description below is

(1) A 4-pitch, 18-tooth drive spur gear (64,

keyed to foldout 7, the left output clutch.

FO-7) is splined to output shaft assembly (51, FO-6) and

(1) An output clutch includes housing

retained by lock plate (66, FO-7), lock tab (67), and bolt

assembly (19, FO-7), piston housing assembly (33),

(68). The gear hubs are supported on straight roller

seven external-tanged disks (27), seven internal-splined

bearings (63 and 69). Inner bearing (63) is contained in

disks (26), eight pins (22), sixteen springs (24) with

a cage in output housing (55), the outer bearing is in a

sixteen guide pins (23) and clutch hub (25). Several

cage in end cover assembly (79).

minor parts complete the group.

(2) A 4-pitch, 40-tooth driven gear (90.

(2) Disks (26 and 27, FO-7) are installed

FO-7) is supported on straight roller bearings (85 and

alternately in housing assembly (19). Pins (22) engage

95). Inner bearing (95) is supported in a cage in the

the tangs on disks (27) and holes in clutch housing

output housing. The outer bearing is supported in a

assembly (19) and piston housing assembly (33). Piston

cage in the end cover assembly. Splines inside the hub

(28) travels in the bore of piston housing assembly (33).

of driven gear (90) are designed to receive the track

The piston housing is installed in clutch housing

sprocket shaft.

assembly (19) and retained by retaining ring (34).

b. Operation.

The output transfer gears

Spring (24) holds piston (28) away from the clutch plates

transmit torque drom the cross shaft to the vehicle drive

when the clutch is released. External splines on clutch

sprockets at a speed reduction ratio of 2.222 to 1.

hub (25) engage the internal-splined disks (26). Internal

Rotation of the track sprockets is opposite to that of the

splines on the clutch hub engage the splines on the

cross shaft.

output shaft.

b. Operation.

2-18.

Output Driven Oil Pump

(1) When the output clutch is applied,

a. Description.

hydraulic pressure pushes piston (28, FO-7) toward

(1) Output driven oil pump assembly (29,

clutch disks (26 and 27) and compresses them against

FO-8) is located on right output housing (63), inside of

inside of housing assembly (19). This locks the entire

end cover assembly (44). The pump, a conventional

clutch assembly together and causes it to rotate as a

gear-type unit, includes a pump body (31), cover (35),

unit when torque is applied from the cross shaft.

two 7-pitch, 8-tooth idler gears (34), and an internal

(2) Housing assembly (19, FO-7) includes

drive gear shaft (33).

the steer planetary sun gear. Hub (25) engages the

(2) A 4-pitch, 13-tooth drive spur gear (25,

output shaft which is splined to steer planetary carrier

FO-8) is keyed to the drive shaft and retained by snap

assembly (55, FO-6). Thus, when the output clutch is

ring (24). The drive gear meshes with transfer drive

applied, two elements of the steer planetary are locked

spur gear (64, FO-7). The slotted end of the shaft on

together. When any two elements of a planetary gear

gear shaft (33, FO-8) protrudes through speedometer

set are locked together the planetary will rotate as a

drive cover (4). The slotted end is machined to receive

unit. Further interconnection of the steer planetary and

a 5/32-inch, heavy-duty speedometer drive cable. The

reverse planetary gear locks two elements of the

speed of the pump (and speedometer drive) is 3.072

reverse planetary, causing it also to rotate as a unit.

times the speed of the power train output (at vehicle

Thus, any rotation of the cross shaft is transmitted by

drive coupling).

the reverse-range sun gear, through interconnected

b. Operation.

components, to the output shaft.

(1) Directional rotation of the pump drive

(3) During straight travel in second, third,

shaft matches the directional rotation of the output shaft.

and fourth gears, both output clutches are engaged.

Therefore, the pump supplies oil under

During normal or pivot steer in second, third, and fourth

gears, only one output clutch is engaged to drive the

2-7