Measuring The Forward Gear Backlash; Adjusting The Forward Gear Shim Thickness (T1); Forward Gear Shim (T1) Selection Chart - SELVA MARINE Kingfish 25 Service Manual

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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
smoothly.
6. Measure the forward gear backlash. See
steps 1–10 in "Measuring the forward
and reverse gear backlash before disas-
sembly" (8-55).
8-63
Lower unit
drive shaft turns
Forward gear backlash:
0.22–0.69 mm (0.0087–0.0272 in)
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
decreased by 0.12 mm.
0.10
0
b
–0.10
–0.20
–0.30
0 5
È
0 5
É
–0.20 –0.17
È Backlash measurement (BL1)
É Shim thickness adjustment
thickness must be
10 15 20 25
a
È (1/100 mm)
10 15 20 25
–0.13 –0.09 –0.06