Volvo Penta 120S, Workshop Manual

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68
Repair - lower gear housing, sailboat drive
Rear bearing housing,
shimming
For when only new bearings have been installed. Use
the previously installed shims in the first instance.
When the gear housing or rear bearing housing is
changed, the shim thickness should be calculated as
below.
33. Shimming, alternative 1
Put the propeller shaft in the gear housing. Install the
outer bearing race for the propeller shaft roller bearing.
Press the bearing race hard and turn the shaft round,
to take up any play in the bearing.
Then use a depth micrometer 9985472 to measure the
distance between the rear plane of the gear housing
and the rear outer bearing race for the propeller shaft.
We call this dimension
Y .
34. Shimming, alternative 2
Alternatively, we can add shims until the outer bearing
race is flush with the gear housing. Clean off all traces
of sealant from the mating surface of the gear housing
against the bearing housing.
IMPORTANT! Make sure that the surface is not
damaged. Do not use steel tools.
Use a steel rule or caliper gauge to check.
35. There is a dimension ( B ) punched on the rear
bearing housing. This dimension is stamped under-
neath the bearing housing, and varies between 50-70.
In this case, the distance is 65 mm.
Example: Y is measured to 1.05 mm in this case.
Shim thickness = Y – B
100
Shim thickness = 1,05 _ 65
100
Shim thickness = 1,05 – 0,65 = 0,40
Shim thickness = 0,40 mm
Shims are available in the following standard thick-
nesses: 0.10 mm, 0.15 mm, 0.35 mm, 0.50 mm.
Use shim thickness 0.35 + 0.10 = 0.45 mm.
B
9985472