John Deere stx38 User Manual
Page 188
5 - 24
3/21/97
THEORY OF OPERATION
POWER TRAIN
TRANSAXLE OPERATION
STX38 (SN 210001— ) & STX46
Function:
The transaxle transmits power from the engine,
through the belt traction drive system, into the
transaxle gear matrix, and out the drive axles to the
rear wheels. The transaxle provides a gear selection of
five forward speeds and one reverse speed.
It also provides the means to interrupt the flow of power
when shifted into neutral.
Major Components:
• Transaxle drive sheave
• Input shaft and pinion gear
• Beveled drive gear, drive shaft with small drive
chain sprocket, drive chain, and drive gears
• Intermediate shifter/brake shaft with shifter fork,
shift collar, shift keys, large drive chain sprocket/
reverse gear, drive chain, and transfer gears
• Idler shaft and combination gear
• Differential gears and axle shafts
• Wheels and tires
Theory of Operation:
Forward:
With engine running and clutch engaged, the transaxle
input sheave (A) turns rapidly in a clockwise direction.
The sheave is retained by a snap-ring and keyed to the
input shaft (B).
The input pinion gear (C), which is splined to the input
shaft and retained by a snap ring, drives the beveled
drive gear (J). The beveled drive gear is splined to the
drive shaft (G), as are the five forward drive gears (I).
A forward gear is selected when the operator moves
the shift lever. The shift linkage moves the shifter fork
(Q), shift collar (P), and shift keys (D) into one of the
selected five transfer gears (E). The selected gear is
now keyed to the intermediate shifter/brake shaft (F).
Power is transferred by the selected gear (E) on the
right side of the shaft to the left-side, splined spur gear
(O).
The spur gear (O) drives the combination gear (N),
splined to the idler shaft (M), which transfers power into
the differential ring gear (L). Power is transferred by the
cross shaft and bevel gears (K) to both drive axles (H)
out to the wheels and tires. The keyed drive wheels are
retained by a e-ring.
M42540
A
B
M42318
C
D
F
E
G
I
J
P
Q
O
N
M
H
L
K
H