MacDon A40D - Removing Knifehead Bearing; Installing Knifehead Bearing

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4.8.4 Removing Knifehead Bearing
The knifehead bearing allows the knifehead pin to rotate within the knifehead as the drive arm strokes the knife back and
forth. If the bearing is worn or damaged, it will need to be replaced.
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A
B
C
D
E
Figure 4.22: Bearing Removal
1. Remove the knife. For instructions, refer to 4.8.2 Removing
Knife, page 144 .
2. Using a flat-ended tool with approximately the same
diameter as plug (D), tap out seal (B), bearing (C), plug (D),
and O-ring (E) from the underside of the head.
NOTE:
The seal can be replaced without removing the bearing.
When changing the seal, check pin (A) and the needle
bearing for wear. Replace the seal if necessary.
4.8.5 Installing Knifehead Bearing
The knifehead bearing, seals, and greasing interval protect the knifehead from the forces of the knife drive output arm. The
seals and bearing require inspection and, when worn, replacement to prevent damage.
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A
B
C
D
E
Figure 4.23: Knifehead Bearing Assembly
1. Place O-ring (E) and plug (D) into the knifehead.
IMPORTANT:
Install the bearing with the stamped end (the end with the
identification markings) facing up.
NOTE:
It may be necessary to temporarily remove the grease
fitting from the knifehead during installation of the
knifehead pin. This will allow any trapped air to escape and
the knifehead pin will seat correctly.
2. Use a flat-ended tool with the same approximate diameter
as bearing (C), and push the bearing into the knifehead
until the top of the bearing is flush with the step in the
knifehead.
3. Install seal (B) into the knifehead with the lip facing
outwards.
IMPORTANT:
To prevent premature knifehead or knife drive box failure,
ensure there is a tight fit between knifehead pin (A) and
the needle bearing, and between the knifehead pin and the
output arm.
4. Install the knife. For instructions, refer to 4.8.3 Installing Knife, page 145.
MAINTENANCE AND SERVICING