SELVA MARINE Kingfish 25, Service Manual

Page: 285 / 398

LOWR
Lower unit
8-67
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 thick-
ness 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.
• 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 table below selection chart shows the
shim thickness adjustments for the points
marked on the chart.
4. Calculate the new reverse gear shim
thickness (T2).
Calculation formula:
New reverse gear shim thickness (T2) = Cur-
rent reverse gear shim thi Shim
thickness adjustment
Example:
If the current reverse gear shim thickness is
0.62 mm and the shim thickness adjustment
is 0.24 mm, then
(T2) = 0.62 mm + 0.24 mm
= 0.86 mm
If the current reverse gear shim thickness is
0.62 mm and the shim thickness adjustment
is –0.22 mm, then
(T2) = 0.62 mm + (–0.22) mm
= 0.62 mm – 0.22 mm
= 0.40 mm
TIP:
• Use the fewest number of shims to achieve
the required shim thickness.
• If the calculated shim thickness cannot be
obtained with a combination of the avail-
able shims, decrease the shim thickness by
0.01 mm.
5. Install the shims (T2) and propeller shaft
housing assembly.
Available shim thicknesses:
0.10, 0.12, 0.15, 0.18, 0.30, 0.40,
0.50 mm