Replacing The Caster Fork - Otto Bock 490E75 Series Service Manual

4.10.4

Replacing the caster fork

Prerequisites:
Optional: Move the seat to the lowest seat height (see Page 15).
Switch off the control unit and deactivate the main fuse (see Page 15).
If necessary: Remove the legrests.
Jack up the wheelchair (see Page 14).
Tools: Small and medium slotted screwdriver; Allen wrench size 5; torque wrench with Allen insert size 5
Removing the caster fork
1) Remove the caster wheel (see Page 57).
2) Optional: Remove the caster wheel splash guard (see Page 58).
3) Pry out and remove the cover cap on the caster wheel swing arm (see Fig. 123, item 1; see Page 57).
4) CAUTION! Pinching, crushing, blows due to loosened caster fork. Actively secure the caster fork against
falling. Note the installed position of the screw connection and washers.
Loosen and remove the screw on the caster fork with 1 friction washer, 1 washer and 1 Belleville washer (see
Fig. 123/124, item 2).
5) Carefully pull the caster fork out of the caster wheel swing arm and set it aside in a safe place.
INFORMATION: The caster wheel bearings remain in the caster wheel swing arm. To replace the bearing
set, see Page 60.
6) Optional: Remove the sleeves of the track stabiliser from the caster fork (see Fig. 124, item 3; see Page 62).
7) Optional: Remove the stopper of the caster wheel swivel lock from the caster fork (see Fig. 124, item 4; see
Page 61).
Installing the caster fork
1) Optional: Attach the stopper of the caster wheel swivel lock to the caster fork (see Fig. 124, item 4; see
Page 61).
2) Optional: Attach the sleeves of the track stabiliser to the caster fork (see Fig. 124, item 3; see Page 62).
3) Carefully insert the caster fork into the caster wheel swing arm with the bearing set.
4) Position 1 friction washer, 1 washer and 1 Belleville washer on the caster fork according to their original installed
position.
INFORMATION: Position the friction washer on the caster fork such that the 2 brackets of the friction
washer extend down into the axle of the caster fork.
5)
pushed.
6) Close the caster wheel swing arm with the cover cap (see Fig. 123, item 1; see Page 57).
7) Optional: Install the caster wheel splash guard (see Page 58).
8) Attach the caster wheel (see Page 57).
123
490E75=0_C
friction torque of 1.1 Nm (see Fig. 123, item 2).
124
Service work
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