SECTION 00 -- GENERAL INFORMATION -- CHAPTER 2
00-10
BREAKAWAY LATCH
The mower can be operated at high speeds depend-
ing on crop and field conditions. In rough field condi-
tions, the ground speed should be reduced. The
mower is protected with a breakaway system. If an
obstruction is hit, the breakaway latch, 1, will break
away and the cutter bar will swing rearward.
NOTE: If the latch releases, stop the tractor immedi-
ately and disengage the PTO.
To reset the cutter bar, back the tractor and mower
until the cutter bar latches and is in its normal posi-
tion. Do not raise the cutter bar to re- latch the break-
away.
Check for any cutter bar damage if an obstruction is
encountered.
The breakaway latch consists of a spring loaded
pawl and dog. The spring mount is designed to pro-
vide a range of adjustment for the dif ferent widths of
mowers and different operating conditions; initially,
adjust the spring length, A, as follows:
MDX71 Disc Mower: 6-3/4″
MDX81 Disc Mower: 6-1/2″
MDX91 Disc Mower: 6-1/4″
If the disc mower is operated in rough terrain, and ex-
cessive breakaways are experienced, the spring
may be further tightened as necessary to eliminate
nuisance breakaways.
NOTE: Do not tighten spring to a length less than
5-7/8
″
or structural failure of the mower may occur.
9
If the spring nut is fully tightened, and excessive
breakaways are still experienced, check the follow-
ing areas:
• The disc mower is properly attached to the tractor
as described in the “General Information” section
of the operator’s manual and this repair manual.
If the disc mower is not properly attached, the
performance of the breakaway will be affected.
• Insufficient cutter bar flotation force. With the
flotation properly adjusted, it should be possible
to lift the outer end of the cutter bar with approx.
150 lbs force. In rougher fields, it may be neces-
sary to further lighten the flotation force.
• The tractor hydraulic valve controlling the lift cyl-
inder must be in the float position, to allow the
cutter bar to float independently. If the valve is not
in float, the cutter bar will be affected by tractor
motion in the field.
• Excessive ground speed for field conditions. If
the stubble height is erratic, and the mower is
bouncing excessively, the operator is travelling
too fast for the conditions.
• Excessive wear on the dog may cause repeated
breakaways. If the dog appears to be worn, re-
move it and rotate it to use the opposite ramp sur-
face.
• Dog mounting bolts loose. The dog is retained
with two 1/2″ cap screws. If these cap screws
loosen up, the dog will tip rearward, increasing
the ramp angle. These two cap screws should be
secured with a locking agent and torqued to 83
ft lbs (112.5 N⋅m).