Section V. DESCRIPTION, OPERATION, AND DATA (MODEL T-136-21)

TM 9-2520-246-34

Section V. DESCRIPTION, OPERATION, AND DATA (MODEL T-136-21)

which moves the synchronizer into contact with the

4-18. General. This section provides repair

input shaft low-speed gear or the input shaft high-

instructions for the sprag equipped transfer, model T-

speed gear. Power is distributed to all three axles,

136-21 (See fig. 4-26 and 4-27.)

although the overrunning sprag units allow the front

wheels to turn freely until the rear wheels lose

4-19. Description and Operation.

traction, at which time the front wheels are engaged in

drive also.

a. Description. Sprag equipped transfer, model T-

136-21, is a 2-speed synchromesh unit driven from the

(1) Low Range. When the transfer is shifted to

transmission by a propeller shaft. The transfer

low range, the synchronizer assembly is moved

distributes power to front and rear axles through the

forward on the input shaft to engage the input shaft

propeller shafts. In addition to high and low speeds,

low-speed gear which is in mesh with the idler shaft

the transfer gearing is designed to drive the front axle

low-speed gear. Because the low-speed gear is keyed to

slightly slower than the rear axles and this difference

the idler shaft, the power flow is through the idler

in speed is taken up by an overrunning sprag unit on

shaft gears, to the rear and front output shaft and

the front output shaft during normal operation. When

shaft gears, and to the companion flanges.

the rear wheels lose traction, the sprag unit

automatically engages, causing the front wheels to

(2) High Range. When the transfer is shifted into

drive the vehicle also. The handbrake drum is

high range, the synchronizer assembly is moved

mounted on the transfer-rear-output-shaft companion

rearward on the input shaft to engage the input shaft

flange. (See fig. 4-27.)

high-speed gear which is in mesh with the idler shaft

high-speed gear. Because the high-speed gear is keyed

to the idler shaft, power flow is through the idler shaft

b. Operation. The selection of high or low range in

gears to the rear and front output shaft and gears.

the transfer is accomplished by a shifting mechanism,

Figure 4-26. Sprag Quipped Transfer Model T-136-21 -- Front View.

4-19