Measuring The Forward Gear Backlash; Adjusting The Forward Gear Shim (T2) Thickness - Yamaha F225F Service Manual

LOWR

Measuring the forward gear backlash

• Spray anti-rust lubricant on the gears 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.
1. Install the original forward gear shims
and propeller shaft housing assembly.
See step 2 in "Installing the propeller
shaft housing assembly" (8-79) and steps
4–6 in "Installing the propeller shaft hous-
ing assembly" (8-29).
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. Check that the drive shaft turns smoothly.
3. Measure the forward gear backlash. See
steps 2–9 in "Measuring the forward gear
backlash and reverse gear backlash
before disassembly" (8-84).
Forward gear backlash:
0.18–0.76 mm (0.0071–0.0299 in)
TIP:
In the "Forward gear shim (T2) selection
chart," use the round-down average for the
backlash measurement (BL2).
Adjusting the forward gear shim (T2)
thickness
1. Remove the propeller shaft housing
assembly and original forward gear
shims. See steps 1–5 in "Removing the
propeller shaft housing assembly" (8-16)
and step 2 in "Removing the propeller
shaft housing assembly" (8-73).
8-91
Lower unit
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 (T2)
thickness adjustment using the "Forward
gear shim (T2) selection chart" according
to the backlash measurement (BL2) from
"Measuring the forward gear backlash."
See "Forward gear shim (T2) selection
chart" (8-93).
Example:
Backlash measurement (BL2) = 0.10 mm a
Forward gear shim (T2) thickness adjustment
= 0.34 mm b
The current shim
increased by 0.34 mm.
0.60
b
0.40
0.20
0
0 5
a
A
0 5
B
0.44 0.39 0.34 0.26
A Backlash measurement (BL2)
B Shim thickness adjustment
thickness must
10 15 20 25
A (1/100 mm)
10 15 20 25
0 0
be
3
3
0