Move equipment to extreme positions in
every direction to ensure that retaining fasteners are
secure and the isolators have not sagged.
Prior to any attempt to install
vibration isolators, the high, or low
side, must be found. Each Isolator
has a low side and a high, or load
side. In some instances, the words
LOAD SIDE will be stamped in the
high side of the isolator to facilitate
Inspection of Vibration Isolators. To prevent
unsatisfactory isolation and eliminate damage, vibration
isolators shall be inspected and replaced in accordance
with the applicable phase maintenance inspection
checklist. The following are general inspection
procedures for all types of vibration isolators.
Using a standard thickness gauge or 6
inch scale, measure vertical and horizontal clearance
between isolated load (equipment case, mounting base,
or instrument panel), and nearest support structure
(isolator mounting cup, mounting base, or aircraft
structure) with vibration isolators with any vertical or
horizontal clearances of less than 1/16 inch.
Move equipment or instrument panel to
extreme positions in every direction to determine if
Isolators have sagged, or retaining rivets or holddown
screws are loose
When elastic rubber parts of open-
type vibration isolators are stretched to their extreme
position, examine rubber for cracks, or separation of
rubber to metal bond. Replace isolators with any of
these conditions visible.
vibration isolator mounting base is moved to extreme
positions in all directions, examine sponge rubber or
metal mesh pads for deterioration and permanent
packing. Replace vibration Isolators with cracked or
deformed pads which seriously affect isolation efficiency
of mounting system.
Figure 9-40. Open-Type Vibration Isolators