5. Inspect the splines of the drive shaft for wear or
damage. Replace the drive shaft as necessary.
6. If necessary, remove the snap ring (C,
Figure
29
), and slide the cover (D) and its dust seal from
the drive shaft.
7. Installation is the reverse of removal.
a. Use a new snap ring when installing the
gearcase cover on the drive shaft.
b. Apply molybdenum disulfide grease to the
drive shaft splines.
c. Seat the spring against the pinion gear nut.
d. Apply Yamaha Bond No. 1215 or an equiva-
lent liquid gasket to the mating surfaces on
the gearcase cover (D,
Figure 29
) and on the
final gearcase.
e. Torque the final gearcase cover nuts to 42
N•m (31 ft.-lb.).
Gear Lash Measurement
A dial indicator, a 14 × 100 mm bolt and the
Yamaha gear lash tool (part No. YM-01230 or
90890-01230) are needed to measure backlash.
1. Drain the oil from the final gearcase as described
in Chapter Three.
2. Remove the final drive assembly and remove the
drive shaft from the final gearcase (this chapter).
3. Secure the gearcase in a vise with soft jaws so
the drain hole faces up.
CAUTION
Do not overtighten the 14 × 100 mm
bolt. Finger tight is sufficient.
3. Turn a 14 × 100 mm bolt (
Figure 30
) into the
drain hole and finger-tighten the bolt enough to
hold the ring gear.
4. Install the gear lash tool (A,
Figure 31
) onto the
gear coupling.
5. Secure a dial indicator (B,
Figure 31
) in place so
the indicator’s plunger rests against the gear lash
tool. The plunger must rest at a point 54.5 mm (2.1
in.) from the center of the pinion gear assembly (C,
Figure 31
).
6. Gently rotate the gear coupling from tooth en-
gagement to tooth engagement. Record the reading
on the dial indicator.
7. Remove the gear lash tool and rotate the drive
pinion 90°.
8. Measure the gear lash again and record this mea-
surement.
9. Take two more measurements, rotating the drive
pinion 90° prior to each measurement.
10. Compare the four measurements to the specifi-
cation in
Table 1
. The gear lash must be adjusted if
any measurement is outside the specified range.
Gear Lash Adjustment
1. Working in a criss-cross pattern, evenly loosen
the nuts (A,
Figure 32
) and bolts (B) on the ring
gear bearing housing. Once all the hardware is
loose, remove the nuts and bolts. Watch for the
washer behind each nut.
2. Remove the bearing housing and the O-ring.
340
CHAPTER TWELVE
29
30
14 × 100 mm
bolt
