New Holland 499 Operator's Manual page 74

REMOVING AND REPLACING KNIFE
ASSEMBLIES
WARNING
When removing or installing a knife assembly, do
not hold down the sections with fingers or any
short object that could slip and result in loss of,
or injury to, fingers.
Removal
To remove a knife assembly, remove knife head bolt,
1. A 13/16" socket fits the nut and a 3/4" wrench fits
the bolt head. The nut and bolt are tapered to fit
countersunk holes in the rocker arms, 2. Use an
extension and socket through hole, 3, to loosen the
connecting rod bolt, 4.
If the knife is hard to remove because guards or
knives are bent, loosen the guard bolts.
IMPORTANT: The rubber bushings in the knife head
and connecting rod will last much longer if the knife
is moved to the center of its stroke before tightening
bolts, 1 and 4. The knife will be in center-stroke if a
socket wrench installed through frame hole, 3, lines
up with the connecting rod bolt, 4.
IMPORTANT: Straighten the knife assembly if it is
bent.
Hold the knife head and sight along the knife back.
The knife must be straight. Rotate the knife 1/4 turn
and recheck for bends. To remove a bend, clamp the
knife back in a vise. Another way to remove a bend
is to lay the high spot on a tire or the frame. Press at
each side of the bend until the knife is straight. Do not
straighten the knife with a hammer as the knife back
may be damaged.
Riveted Knives
Check the knife assemblies for loose rivets. To
tighten a rivet; place the rivet over a solid support.
Strike the rivet with a heavy hammer to swell the rivet.
If several rivets are loose, it is usually easier to
remove the knife assembly and then reseat the
rivets.
SECTION 4 - MAINTENANCE
10004739
4-14
4
3
1
2
16