Standard Sickle Guards And Hold-Downs - MacDon 912 Operator's Manual

Guards (Standard)
Check daily that guards are aligned to obtain
proper shear cut between sickle section and
guard. Sickle sections should contact shear
surface of each guard.
Check guards alignment by sighting down
cutterbar. Align guards with guard straightening
tool provided, as shown.
To bend guard tips up, position tool as shown at
(B) and pull up.
To bend tips down, position tool as shown at (C)
and push down.
See "Unplugging the Header" in Operation section
for tool storage.
SERVICE PARTS NOTE: The first two guards at
each end of cutterbar (double knife header) and at
L/H end only (single knife headers) are special
guards without the rear wear bar. To prevent
interference with the knife back and avoid damage
to the drive, these end guards must be serviced
with the correct service part. (See Parts Catalog).
Sickle Hold-Downs (912 & 922 Headers)
Check daily that sickle hold-downs are set to
prevent sickle sections from lifting off guards but
still permit sickle to slide without binding. Set hold-
downs after guards are aligned.
To set hold-downs:
1. Use the unplug wrench (A) with the flattened
end against the front edge of the hold down
(B). Strike the end of the wrench with a heavy
hammer. This allows adjustment of hold-down
arch (B) without "pinching" sickle. Clearance
from hold-down to sickle section should be
.020 in. (0.5 mm).
2. After adjusting all sickle hold-downs, run
header at a low engine speed and listen for
noise due to insufficient clearance. Re-adjust
as necessary by placing a .020 in. (0.5 mm)
shim between hold-down and section, then
striking the hold-down arch (B) with a hammer.
Form # 46620
MAINTENANCE/SERVICE
46
B
BENDING GUARD TIPS UP
A C
BENDING GUARD TIPS DOWN
A
SETTING SICKLE HOLD-DOWNS
SETTING SICKLE HOLD-DOWNS
B
Issue 11/06