Yamaha MM700A Manual page 33

GENERAL INFORMATION
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Bearing
Blocks
Shaft
Bearing
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Press bed
NOTE
Unless otherwise specified, install bearings
with the manufacturer's mark or number
facing outward.
Removal
While bearings are normally removed only when dam-
aged, there may be times when it is necessary to remove a
bearing that is in good condition. However, improper
bearing removal does damage the bearing and maybe the
shaft or case half. Note the following when removing
bearings.
1. When using a puller to remove a bearing from a shaft,
take care that shaft is not damaged. Always place a piece
of metal between the end of the shaft and the puller screw.
In addition, place the puller arms next to the inner bearing
race. See Figure 52.
2. When using a hammer to remove a bearing from a
shaft, do not strike the hammer directly against the shaft.
Instead, use a brass or aluminum spacer between the ham-
mer and shaft (Figure 53) and make sure to support both
bearing races with wooden blocks as shown.
3. The ideal method of bearing removal is with a hydrau-
lic press. Note the following when using a press:
a. Always support the inner and outer bearing races
with a suitable size wooden or aluminum spacer
ring (Figure 54). If only the outer race is supported,
pressure applied against the balls and/or the inner
race will damage them.
b. Always make sure the press ram (Figure 54) aligns
with the center of the shaft. If the ram is not cen-
tered, it may damage the bearing and/or shaft.
c. The moment the shaft is free of the bearing, it will
drop to the floor. Secure or hold the shaft to prevent
it from falling.
Installation
1. When installing a bearing in a housing, apply pressure
to the outer bearing race (Figure 55). When installing a
bearing on a shaft, apply pressure to the inner bearing race
(Figure 56).
2. When installing a bearing as described in Step 1, use
some type of driver. Never strike the bearing directly with
a hammer or the bearing will be damaged. When install-
ing a bearing, use a piece of pipe or a driver with a diame-
ter that matches the bearing race. Figure 57 shows the
correct way to use a driver and hammer to install a bear-
ing.
3. Step 1 describes how to install a bearing in a case half
and over a shaft. However, when installing a bearing over
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