Section II. DESCRIPTION, OPERATION, AND DATA (MODEL 3053A)

TM 9-2520-246-34

Section II. DESCRIPTION, OPERATION, AND DATA

(MODEL 3053A)

(overdrive) synchronizer and to the mainshaft. (See fig. 3-

3-4. General. The description and operation of the

15, view B.)

transmission model 3053A is very similar to that of

transmission model 3052. Therefore, this section will

3-6. Data.

refer to Section I, where applicable, to avoid

repetition. Only the differences will be given in this

National stock number . . . . . . . . . . 2520-00-884-4833

section.

Ordnance number . . . . . . . . . . . . . . . . . . . . . . 10872096

Make . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Spicer

3-5. Description and Operation.

Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3053A

Type . . . . . . . . . . . . . . . . . . . . . . . . . . . Synchromesh

a. Description. Figure 3-1 shows the transmission

Speeds:

model 3053A used on the 2-ton, 6x6, multifuel

Forward . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

engine vehicles without front winch equipment. This

Reverse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

transmission can also power a front winch by means

Gear types:

of a power takeoff mounted on the left side of the

Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Helical

transmission. (See fig. 3-2.) The construction of

Mainshaft (except first-reverse) . . . . . . . . . Helical

transmission model 3053A is almost identical to that

Mainshaft first-reverse . . . . . . . . . . . . . . . . . . . Spur

of transmission model 3052, except for the fourth and

Countershaft (except first) . . . . . . . . . . . . . . Helical

fifth gear arrangements. This difference is shown by

Countershaft first . . . . . . . . . . . . . . . . . . . . . . . Spur

comparison between figures 3-13 and 3-6 and figures 3-14

Reverse idler . . . . . . . . . . . . . . . . . . . . . Spur-helical

and 3-8.

Bearings:

Input shaft . . . . . . . . . . . . . . . . . . . . . . .

b. Operation.

Ball

Mainshaft front . . . . . . . . . . . . . . . . . Straight roller

Mainshaft rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ball

(1) Power Flow. Power flow for transmission

Countershaft front . . . . . . . . . . . . . Straight Roller

model 3053A is the exact opposite of the power flow

Countershaft rear . . . . . . . . . . . . . . . . . . . . . . . . Ball

for transmission model 3052. See figure 3-15 for the

Reverse idler . . . . . . . . . . . . . . . . . . . Straight roller

difference in power flow. See figure 3-12 for first-,

Input shaft size:

second-, and third-speed power flow.

Spline diameter . . . . . . . . . . . . . . . . . . . . . . 1.499 in.

Number of splines . . . . . . . . . . . . . . . . . . . . . . . . . . 10

(2) Fourth-Speed Power Flow. Power is

Full length of splines . . . . . . . . . . . . . . . . . 2.375 in.

transmitted from the input gear, which is coupled to

Mainshaft (output end) size:

the mainshaft by the fourth-fifth synchronizer, directly

Spline diameter l . . . . . . . . . . . . . . . . . . . . . 1.499 in.

to the mainshaft. Because the interlocking action of

Number of splines . . . . . . . . . . . . . . . . . . . . . . . . . . 10

the synchronizer in effect makes one continuous shaft

Full length of splines . . . . . . . . . . . . . . . . .1.906 in.

of the input shaft and mainshaft, the drive here is

Gear ratios:

direct; i.e., a 1-to-1 ratio. (See fig. 3-15, view A.)

First speed . . . . . . . . . . . . . . . . . . . . . . . . . . 5.02 to 1

Second speed . . . . . . . . . . . . . . . . . . . . . . . . 2.78 to 1

(3) Fifth-Speed (Overdrive) Power Flow. Power

Third speed . . . . . . . . . . . . . . . . . . . . . . . . . 1.62 to 1

is transmitted by the countershaft fifth-speed

Fourth speed . . . . . . . . . . . . . . . . . . . . . 1.00 to l.00

(overdrive) gear to the mainshaft fifth-speed

Fifth speed (overdrive) . . . . . . . . . . . . . . . . 0.79 to 1

(overdrive) gear, which is coupled to the fourth-fifth

Reverse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.90 to 1

3-9