TM-9-2520-215-34

TM 9--2520--215--34

0005 00--26

THEORY OF OPERATION -- CONTINUED

0005 00

TORQUE PATHS THROUGH TRANSMISSION – Continued

Torque Path in Neutral, Converter Drive, Right Steer

NOTE

Refer to Torque Path in Neutral, Converter Drive, No Steer and Hydraulic System, Neutral,

Converter Drive, Right Steer Schematic Views.

Refer to Torque Path in Neutral, Converter Drive, No Steer for the explanation of conditions in neutral. The explana-

tions below are expanded to included steer action in neutral.

To obtain steer in neutral, the engine speed must be sufficient to cause rotation of the turbine (by converter action).

When the converter shaft rotates, the steer gear train rotates. Thus, counterclockwise rotation is imparted to both

right and left steer clutch drive gears.

The right steer clutch is engaged, locking the right steer planetary sun gear to the steer clutch drive gear. This causes

the sun gear to rotate counterclockwise also.

An idler gear, in mesh with the right tie shaft drive gear and tie shaft pinion, rotates clockwise. This drives the tie shaft

counterclockwise. A pinion at the left end of the tie shaft, in mesh with the left tie shaft drive gear, rotates the left tie

shaft drive gear and left steer planetary sun gear clockwise.

The right and left steer planetary sun gears rotate in opposite directions instead of remaining stationary as they do in

straight travel. In neutral, the steer planetary ring gears are stationary. They become reaction members while the

normally stationary sun gears become the driving members.

Since the right steer planetary sun gear rotates counterclockwise, the carrier is also forced to rotate counterclockwise,

within the stationary ring gear. This causes the transmission output to rotate counterclockwise, driving the right ve-

hicle track in reverse. The left output steer sun gear rotates clockwise, causing the output rotation at the left side to

be clockwise. The left vehicle track is driven forward. The tendency of the right and left steer planetary ring gears to

rotate is canceled. This happens because the gears are splined to the driven bevel gear shaft and their reactions are

in opposite directions.

In neutral steer, the vehicle will pivot around its center without forward or reverse movement.

Refer to this work package for the ratios involved in neutral steer.

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