MacDon FD70 for Combine Operators - Manual (Page 180)

SECTION 10. MAINTENANCE AND SERVICING
Form 169006
178
Revision D
10.11.9.3 Sickle Drive Timing
Double knife D60 Harvest Headers 35 FT and
smaller require that sickles are properly timed to
move in opposite directions.
To adjust sickle timing, proceed as follows:
a. Remove right sickle drive belt. Refer to Section
10.11.9.2.2 Removal: Right End Timing Belt.
b. Rotate left wobble box driven pulley (A) clockwise
until left sickle (B) is at the center of the inboard
stoke (moving towards center of header).
NOTE
Center stroke is when sickle sections
are centered between guard points as
shown.
c. Rotate right wobble box pulley (C) counter
clockwise until right sickle (D) is at the center of
the inboard stroke.
d. Install right wobble box drive belt, and adjust
tension. Refer to Section 10.11.9.2.3 Installation:
Right End Timing Belt.
IMPORTANT
To maintain timing, wobble box driver
and driven pulleys must not rotate as
the belt is tightened.
e. Check that timing belts are properly seated in
grooves on both driver and driven pulleys.
f. Check for correct sickle timing by rotating the
drive slowly by hand, and observe sickles where
they overlap at center of the header.
IMPORTANT
Sickles must move in opposite
directions, and must begin moving at
exactly the same time.
If timing is off, proceed as follows:
1. Loosen right belt sufficiently to allow skipping
the belt one or more teeth as required. Refer
to Section 10.11.9.2.1 Tension Adjustment:
Timing Belt.
2. If right sickle “leads” left sickle, rotate RIGHT
SIDE driven pulley (C) clockwise.
3. If right sickle “lags” left sickle, rotate RIGHT
SIDE driven pulley (C) counter clockwise.
4. Tighten right belt.
RIGHT
SICKLE
LEFT
SICKLE
DIRECTION OF
MOVEMENT
SECTIONS CENTERED
BETWEEN GUARDS
B
D
A
C
RIGHT
SICKLE
LEFT
SICKLE
DIRECTION OF
MOVEMENT
SECTIONS CENTERED
BETWEEN GUARDS
B
D