SERVICE MANUAL & ICA
8750 AMPHIBIAN/SEAPLANE FLOATS ON CESSNA 208/208B
Revision C
Page 49 of 104
P/N 1005723 Doc. No. W8750-24-01
4.1 MAIN GEAR RETRACTION
DESCRIPTION (CONTINUED)
In addition to the over center locking provided
by the rod linkages and actuator arm for the gear
extended position, a second down locking
method is provided as well. The geometry of
the main gear drag link, oleo-pneumatic shock
strut and the top arm assembly, provide an
additional over center locking method. The
force vector from the oleo, (directed in line with
the centerline of the oleo assembly) rotates the
contacting face on the top arm assembly into
contact with the main gear top mount at all
positions of oleo stroke. This transfers the
landing load into a structure designed to
withstand the generated landing forces, as well
as prevents the top arm from rotating and
collapsing the main landing gear.
There are two proximity switches on each main
gear unit. One for sensing gear up position, and
the other for gear down position. These are
easily replaceable and can essentially be
adjusted during maintenance, see figure 4-4A
and 4-5. The proximity sensors have a built in
LED to indicate when they are sensing the gear
position. This feature greatly aids in the setup
and servicing of the sensors.
There are several service points on the main
landing gear to pay attention to during
maintenance. Grease zerks are located on the
pivots of the main gear draglinks, each wheel
axle, top and bottom pivot points on the oleo-
pneumatic shock strut, and the rotation point of
the top arm assembly, see figure 4-3. The
adjustable rod end bearings are permanently
sealed and do not require servicing. Inspect the
rod ends for freedom of movement and
corrosion. Replace the rod ends when
necessary. Depending on the operating
environment, greasing requirements may vary.
Highly corrosive environments, such as salt
water, may require more frequent inspections.
Regardless, the gear should be inspected
visually at least every 25 hours for cleanliness
and proper lubrication.