Reverse Gear Shim (T1) Selection Chart - Yamaha F150B Service Manual

2. Measure the thickness of each original
shim(s) (T1) in 2 places.
TIP:
Do not reuse a shim if it is deformed or
scratched.
3. Determine the reverse
thickness (T1)

"Reverse gear shim (T1) selection chart"

according to the truncated average (BL1)
from "Measuring
backlash."
Example:
(BL1) = 0.70 mm a
(T1) adjustment = 0.17 mm b from the
"Reverse gear shim (T1) selection chart."
The current shim
increased by 0.17 mm.
0.40
0.20
b
0
–0.20
–0.40
0 5 10 15
A (1/100 mm)
A
0 5 10 15
B
–0.30 –0.27 –0.23 –0.20
A
Backlash measurement (BL1)
B
Shim thickness adjustment
TIP:
• If the shim thickness adjustment value is
positive, the current shim thickness must be
increased by that amount and, if the value
is negative, the current shim thickness must
be decreased 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.
gear shim
adjustment in the
the reverse gear
thickness must be
65 70 75
a
70 75
0.17 0.2
Shimming (counter rotation model)
• The values for the shim thickness adjust-
ments specified in the selection chart are
intended to achieve the median value within
the range for the specified forward or
reverse gear backlash.
• The selection chart table shows the shim
thickness adjustments for marked points on
the chart.
4. Calculate the new reverse gear shim
thickness (T1) as same way in the
example.
Calculation formula:
New reverse gear shim thickness (T1) = Cur-
rent reverse gear shim thickness + Shim
thickness adjustment
Example:
If the current reverse gear shim thickness is
1.00 mm and the shim thickness adjustment
is –0.23 mm, then
(T1)= 1.00 mm + (–0.23) mm
= 1.00 mm – 0.23 mm
= 0.77 mm
Available shim thicknesses:
0.10, 0.12, 0.15, 0.18, 0.30, 0.40, and
0.50 mm
TIP:
• Use the least number of shims to achieve
the required shim thickness.
• If the calculated shim thickness cannot be
obtained with a combination of the available
shims, increase the shim thickness by
0.01 mm.
5. Install the shim(s) (T1) and roller bearing.
0
1
2
3
4
5
6
7
8
9
10
A
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