Yamaha F400A 2022 - Page 443

Shimming (regular rotation model)
8-44
c. While turning the shift rod toward the R
position using the specified torque,
turn the drive shaft slowly clockwise
and counterclockwise and measure
the backlash between where the drive
shaft stops in each direction.
TIP:
Do not turn the drive shaft using too much
force. Otherwise, the reverse gear will turn,
leading to incorrect measurements.
d. Turn the drive shaft 180° clockwise,
and then measure the backlash again.
TIP:
• Measure the backlash at 4 points: “a”, “b”,
“c”, and “d”, turning the drive shaft 180°
clockwise after each measurement.
• Write down the measurement data in the
shimming check sheet.
e. Determine the backlash average, and
then round down the average to 2 dec-
imal places.
Example:
(mm)
f. Check that the reverse gear backlash
average is within specification.
TIP:
Repeat steps from the selection of the forward
gear shim (T1) and reverse gear shims (T2) if
the reverse gear backlash is out of specifica-
tion.
g. Remove the special service tools.
Shift rod socket “1”
90890-06950
T
R
.
.
Specified torque
10 N·m (1.0 kgf·m, 7.4 lb·ft)
b
a
Measurement point “a” 0.45
Measurement point “b” 0.46
Measurement point “c” 0.46
Measurement point “d” 0.44
Average 0.4525
Round-down average 0.45
Reverse gear backlash
0.39–0.83 mm (0.0154–0.0327
in) (F400ASTU, F400ASTX,
F450AVTU, F450AVTX)
a
b
c
d