SELVA MARINE Fin Whale 225 EFI, Service Manual

Page: 242 / 399

LOWR
Lower unit
6-57
6AL3J11
Selecting the forward gear shim
1. Turn the taper roller bearing outer race
1
2 or 3 times to seat the rollers, and
then measure the bearing height (M5)
and (M6) as shown.
NOTE:
• Select the shim thickness (T2) by using the
specified measurement(s) and the calcula-
tion formula.
• Measure the taper roller bearing at 4 points
to find the height average.
2. Calculate the forward gear shim thick-
ness (T2) as shown in the examples
below.
NOTE:
“ R ” is the deviation of the lower case dimen-
sion from standard, and “ A ” is the deviation of
the propeller shaft housing dimension from
standard. The
“ R ” mark
a
is stamped on the
trim tab mounting surface of the lower case,
and the
“ A ” mark
b
is stamped on the pro-
peller shaft housing in 0.01 mm units. If the
“ R ” mark or “ A ” mark is unreadable, assume
that “ R ” and “ A ” are zero and check the back-
lash when the unit is assembled.
Example:
If
“ M5 ” is 22.95 mm, “ M6 ” is 15.73 mm, “ R ” is
( – 1), and “ A ” is ( – 3), then
T2 = 8.45 + ( – 1)/100 – ( – 3)/100 – 22.95 + 15.73 mm
= 8.45 – 0.01 + 0.03 – 22.95 + 15.73 mm
= 1.25 mm
If “ M5 ” is 22.95 mm, “ M6 ” is 15.73 mm, “ R ” is
( – 1), and “ A ” is (+2), then
T2 = 8.45 + ( – 1)/100 – (+2)/100 – 22.95 + 15.73 mm
= 8.45 – 0.01 – 0.02 – 22.95 + 15.73 mm
= 1.20 mm
Shimming plate
2
: 90890-06701
Digital caliper
3
: 90890-06704
2
M6
Calculation formula:
Forward gear shim thickness (T2) =
8.45 + R/100
– A/100 – M5 + M6
A – 3 B
S6AL6750
b