Measuring The Reverse Gear Backlash; Adjusting The Reverse Gear Shim Thickness (T1) - Yamaha F150A Service Manual

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 the forward gear or
reverse gear backlash, use the original
bearings and shims.
1. Install the original reverse gear shims
(T1) and roller bearing outer race.
TIP:
• If the original reverse gear shims (T1) are
missing, install new shims with a combined
thickness of 1.00 mm.
• Do not reuse a shim if deformed or
scratched.
2. Install the reverse gear assembly, drive
shaft, and pinion. See "Installing the drive
shaft" (8-25).
3. Check that the drive shaft turns smoothly.
4. Install the thrust bearing, pinion shims
(T3), and drive shaft housing.
5. Install the propeller
assembly. See "Installing the propeller
shaft housing assembly" (8-64).
6. Check that the drive shaft turns smoothly.
7. Measure the reverse gear backlash. See
steps 16–19 in "Measuring the forward
gear backlash and reverse gear backlash
before disassembly" (8-69).
Reverse gear backlash (FL150A):
0.24–0.58 mm (0.0094–0.0228 in)
Reverse gear backlash (FL150B):
0.24–0.65 mm (0.0094–0.0256 in)
Adjusting the reverse gear shim
thickness (T1)
1. Remove the roller bearing outer race and
reverse gear shims (T1).
shaft housing
8-76
Shimming (counter rotation model)
2. Measure the thickness of original reverse
gear shim (T1) in 2 places.
TIP:
Do not reuse a shim if deformed or
scratched.
3. Determine the reverse gear shim (T1)
thickness adjustment using the "Reverse
gear shim (T1) selection chart" according
to the backlash measurement (BL1) from
"Measuring the reverse gear backlash".
See "Forward gear shim (T2) selection
chart (FL150A)" (A-16) or See "Forward
gear shim (T2) selection chart (FL150B)"
(A-17).
TIP:
• If the shim thickness adjustment value is
positive, increase the current shim thick-
ness by that amount and, if the value is
negative, decrease the current shim thick-
ness by that amount.
• The gray-colored area on the selection
chart indicates the range of the specified
backlash. Shimming is not required if the
measured backlash is within the gray-col-
ored area.
• The values for the shim thickness adjust-
ments specified in the selection chart are
intended to obtain the median value within
the range for the specified forward gear or
reverse gear backlash.
• The table that follows the selection chart
shows the shim thickness adjustments for
the points marked on the chart.
Example:
Backlash measurement (BL1) = 0.20 mm "a"
Reverse gear shim (T1) thickness adjustment
= –0.14 mm "b"
The current shim
decreased by 0.14 mm.
thickness must be
0
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A