Maintenance Section 4-20
MAINTENANCE
50” FLAIL KNIFE BLADE REPLACEMENT
1 – If knives are damaged or badly worn, they will need to be replaced as a set.
Replacing a single knife can cause severe vibration and possible damage to
the mower. The knife should not be welded on for any reason.
2 - Always replace the knife bolts when replacing the knives. DO NOT REUSE THE
KNIFE BOLTS OR NUTS.
3 – Assemble knives, bushings, bolts and nuts as shown in part section of the
manual.
4 – Install the locking hex nut so that the flat face of the nut is towards the knife.
4 – Apply loctite “271” to threads.
5 – Torque nut to 176 ft lbs. Knife must swing freely.
DO NOT re-use the locking hex nuts for mounting the knives. If hex
nut become loose, or require removal for knife replacement or any
other reason, they must be discarded and replaced with new nuts.
Failure to follow the following warnings and instructions may result
in serious injury or damage to the equipment or property!
1 – The bolts that attach the disk to the spindle must be grade 8. These 5/8 inch
bolts are to be torqued to 204 dry or 184 oiled ft. lbs.
2 – A thread locking agent may be applied to threads of all mounting bolts before they
are installed.
3 – Disks must be inspected daily for hairline cracks between spindle
mounting bolts or around the knife mounting bolts. These cracks indicate
metal fatigue caused by severe abuse. If cracks are present the disk must be
replaced.
4 – Inspect the disk mounting bolts daily when checking tightness of knife mounting
bolts. If a disk mounting bolt is loose, it must be removed, threads cleaned, fresh
thread locking agent applied, and tightened to proper torque value.
5 – If a knife mounting bolt is loose, the self locking nut must be replaced as a safety
precaution. Install bolts through knife and disk from bottom side of disk. Install self
locking nuts and torque them to 1070 dry or 800 oiled ft. lbs. It is then recommended
that the head of the knife mounting bolt be struck sharply with a hammer and self
locking nuts retorqued to 1070 dry or 800 oiled ft. lbs.
REPLACEMENT OF ROTARY DISK