SELVA MARINE Kingfish 25, Service Manual

Page: 284 / 398

8-66
8
Measuring the reverse 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 forward gear or reverse
gear backlash, use the original bearing and
shims.
1. Install the original shims and ball bearing
onto the reverse gear, and then install
the reverse gear assembly into the pro-
peller shaft housing. See “Assembling
the propeller shaft housing assembly” (8-
40) steps 3 and 4.
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 propeller shaft housing assem-
bly into the lower case. See “Installing
the propeller shaft housing assembly” (8-
48).
3. Check that the drive shaft turns
smoothly.
4. Measure the reverse gear backlash. See
steps 11–14 in “Measuring the forward
and reverse gear backlash before disas-
sembly” (8-55).
Adjusting the reverse gear shim
thickness (T2)
1. Remove the reverse gear and reverse
gear shims. See step 1 in “Disassem-
bling the propeller shaft housing assem-
bly” (8-39).
2. Measure the thickness of each original
reverse gear shim in 2 places.
TIP:
Do not reuse a shim if deformed or
scratched.
3. Determine the reverse gear shim thick-
ness (T2) adjustment using the “Reverse
gear shim (T2) selection chart” according
to the round-down average (BL2) from
“Measuring the reverse gear backlash”.
Example:
(BL2) = 0.15 mm
a
(T2) adjustment = –0.39 mm
b
from the
“Reverse gear shim (T2) selection chart”.
The current shim thickness must be
decreased by 0.39 mm.
È
Backlash measurement (BL2)
É
Shim thickness adjustment
Reverse gear backlash:
0.90–1.37 mm (0.0354–0.0539 in)
20 15 10 5 0
20 15 10 5 0
– –0.36 –0.39 –0.43 –0.47 –0.50
–0.60
–0.50
–0.40
–0.30
–0.20
a
b
É
È
É
(mm)
È (1/100 mm)
Shimming (high thrust model)