SELVA MARINE Blue Whale 250 EFI, Service Manual

Page: 216 / 377

LOWR
Lower unit
6-25
6P23H11
2. Calculate the forward gear shim thick-
ness (T1) as shown in the examples
below.
NOTE:
“ F ” is the deviation of the lower case dimen-
sion from standard. The “ F ” mark
a
is
stamped on the trim tab mounting surface of
the lower case in 0.01 mm units. If the
“ F ”
mark is unreadable, assume that “ F ” is zero
and check the backlash when the unit is
assembled.
Example:
If
“ M1 ” is 29.10 mm and “ F ” is (+5), then
T1 = 29.50 + (+5)/100 – 29.10 mm
= 29.50 + 0.05 – 29.10 mm
= 0.45 mm
If “ M1 ” is 29.10 mm and “ F ” is (0), then
T1 = 29.50 + (0)/100 – 29.10 mm
= 29.50 + 0 – 29.10 mm
= 0.40 mm
3. Select the forward gear shim(s) (T1) as
follows.
Example:
If
“ T1 ” is 0.45 mm, then the forward gear
shim is 0.42 mm.
If
“ T1 ” is 0.40 mm, then the forward gear
shim is 0.38 mm.
Selecting the reverse gear shim
1. Turn the ball bearing
1
2 or 3 times, and
then measure the bearing height (M2) as
shown.
NOTE:
• Select the shim thickness (T2) by using the
specified measurement(s) and the calcula-
tion formula.
• Measure the bearing outer race at 3 points
to find the height average.
2. Calculate the reverse gear shim thick-
ness (T2) as shown in the examples
below.
Calculation formula:
Forward gear shim thickness (T1) =
29.50 + F/100
– M1
Calculated numeral
at 1/100 place
Rounded numeral
1, 2 0
3, 4, 5 2
6, 7, 8 5
9, 10 8
Available shim thicknesses:
0.10, 0.12, 0.15, 0.18, 0.30, 0.40, and
0.50 mm
Shimming plate
2
: 90890-06701
Digital caliper
3
: 90890-06704