MacDon 873 Combine Adapter - Manual (Page 25)

Form # 147069 Issue 09/06 23
OPERATION
HEADER ANGLE
The header (or guard) angle can be adjusted flatter or steeper to suit your conditions. Angle range varies with
combine set-up, tire size, adapter down stop position, etc.
See Combine Operator's Manual for header levelling and additional header angle adjustments. For combines
with adjustable face-plate angle, see “Adjustments and Checks” on page 50 to determine if adjustment to face
plate angle is required.
IMPORTANT: A flat header angle is recommended for normal conditions. A flatter header angle reduces sickle
section breakage and reduces soil scooping or build-up at the cutterbar in wet conditions. Use a steeper angle
to cut very close to the ground, or in down crop for better lifting action. The Model 973 and 974 headers have
been designed so the guard angle is flatter than the draper angle. This allows operating at a mid-range header
angle while still benefiting from a flat guard angle.
IMPORTANT: Always check adapter drum clearance to header frame after adjusting header angle. Flattening
the header angle will reduce the clearance to the drum fingers. For units with hydraulic top link, fully retract the
cylinder to check finger clearances.
To adjust header angle with mechanical link
(972 & 973 Headers):
1. Lower cutterbar to ground and continue
lowering to drop feeder house another 2 to 5
inches (50 to 125 mm).
2. Back off the locking collar (A) on top link
turnbuckle.
3. Using a punch in hole in turnbuckle (B), turn to
adjust header angle.
Longer top link = steeper header angle
4. At desired adjustment, tighten locking collar (A)
securely against turnbuckle to fix the position.
Collar should point up as shown to prevent
contact with header frame when header floats
fully up.
HEADER ANGLE HYDRAULIC ADJUSTMENT
An optional kit is available for 972 and 973
Headers which allows adjustment of header angle
from the combine cab by means of a hydraulic
cylinder. This is standard equipment for the 974
Header.
See “Unloading and Assembly” section for
information on assembly and use of this option.
WIDENING THE DELIVERY OPENING (973/974 Headers Only):
In conditions where severe “bridging” is occurring (bulky crop being thrown across the opening), widen the
header side draper opening to allow the crop to fall onto the feed draper. See “Delivery Opening” in your
Header Operators’ Manual for procedure. To achieve smooth feeding after widening opening, add
outboard tines to the adapter drum. See “Tine Installation”, page 32.
NOTE: Check clearance to ensure that RTD fingers will not contact side drapers.
Combine Model
New Delivery
Opening
Qty. of tines to be
added to drum
John Deere, New Holland CX, Lexion (Wide Decks) 1620 mm (63.7”) 2 per side (4 total)
Case 77/80/88, CNH AFX,
New Holland CR 970/980, Lexion (Mid-Size Decks)
1265 mm (49.8”) 2 per side (4 total)
Case 60/66, New Holland CR 1165 mm (45.9”) 2 per side (4 total)
HEADER ANGLE
MECHANICAL ADJUSTMENT
A
B