Yamaha F30A, Service Manual

Page: 176 / 285

LOWR
Lower unit
6-25
67C3K11
2. Measure the propeller shaft housing
height (M3) as shown.
M3 = M3’ – 10 mm
NOTE:
Measure the propeller shaft housing at 4
points to find the height average.
3. Calculate the reverse gear shim thick-
ness (T2) as shown in the examples
below.
NOTE:
“R” is the deviation of the lower case dimen-
sion from standard. The “R” mark
a
is
stamped on the trim tab mounting surface of
the lower case in 0.01 mm units. If the “R”
mark is unreadable, assume that “R” is zero
and check the backlash when the unit is
assembled.
Example:
If “M3” is 96.79 mm and “R” is (–1), then
T2 = 98.00 – 96.79 + (–1)/100 mm
= 98.00 – 96.79 – 0.01 mm
= 1.20 mm
If “M3” is 96.79 mm and “R” is (+3), then
T2 = 98.00 – 96.79 + (+3)/100 mm
= 98.00 – 96.79 + 0.03 mm
= 1.24 mm
4. Select the reverse gear shim(s) (T2) as
follows.
Digital caliper
1
: 90890-06704
Shimming plate
2
: 90890-06701
S67C6075
1
2
S67C6076
M3’
10 mm
(0.39 in)
1
2
M3
Calculation formula:
Reverse gear shim thickness (T2) =
98.00 – M3 + R/100
Calculated number Rounded number
0.01–0.02 0.00
0.03–0.05 0.02
0.06–0.08 0.05
0.09–0.10 0.08
Available shim thicknesses:
0.10, 0.12, 0.15, 0.18, 0.30, 0.40, 0.50
mm
S67C6078
a