SELVA MARINE Kingfish 25, Service Manual

Page: 281 / 398

LOWR
Lower unit
8-63
Measuring the forward gear backlash
• Spray anti-rust lubricant on the gear and
bearings before installation. Do not apply
gear oil to the parts. Otherwise, correct
measurements cannot be obtained.
• Keep the parts free of foreign material,
such as dirt and lint.
• When measuring the forward gear or
reverse gear backlash, use the original
bearings and shims.
• Use heat-resistant gloves. Otherwise,
burns could result.
• To prevent fires, remove any flammable
substances, such as gasoline and oil,
around the working area.
• Keep good ventilation while working.
1. Install the original forward gear shims
and the taper roller bearing outer race
into the lower case. See steps 2 and 3 in
“Assembling the lower case” (8-16).
TIP:
• If the original shims are missing, install new
shims with a combined thickness of 0.50
mm.
• Do not reuse a shim if deformed or
scratched.
2. Install the forward gear assembly, drive
shaft, pinion, and pinion nut. See steps 1
and 2 in “Installing the shift rod, oil seal
housing, and drive shaft” (8-47).
3. Check that drive shaft turns smoothly.
4. Install the propeller shaft housing assem-
bly. See “Installing the propeller shaft
housing assembly” (8-48).
5. Check that the drive shaft turns
smoothly.
6. Measure the forward gear backlash. See
steps 1–10 in “Measuring the forward
and reverse gear backlash before disas-
sembly” (8-55).
Adjusting the forward gear shim
thickness (T1)
1. Remove the taper roller bearing outer
race. See step 3 in “Disassembling the
lower case” (8-15).
2. Measure the thickness of each original
forward gear shim in 2 places.
TIP:
Do not reuse a shim if deformed or
scratched.
3. Determine the forward gear shim thick-
ness (T1) adjustment using the “Forward
gear shim (T1) selection chart” according
to the round-down average (BL1) from
“Measuring the forward gear backlash”.
Example:
(BL1) = 0.15 mm
a
(T1) adjustment = –0.09 mm
b
from the
“Forward gear shim (T1) selection chart.”
The current shim thickness must be
decreased by 0.12 mm.
È
Backlash measurement (BL1)
É
Shim thickness adjustment
Forward gear backlash:
0.22–0.69 mm (0.0087–0.0272 in)
–0.30
–0.20
–0.10
0
0.10
25 20 15 10 5 0
25 20 15 10 5 0
–0.06 –0.09 –0.13 –0.17 –0.20
É
(mm)
È (1/100 mm)
a
b
È
É