Service Manual

Service Dealer’s Guide to Great Quality of Cut 4 - 23
Checking and Adjusting the Blade Level
Adjusting Front-to-Rear Pitch
The mower blade should be between 1/16- 5/16 inch
(1.6-7.9mm) lower in front than in the rear. If
adjustment is necessary, proceed as follows:
1. To adjust the front-to-rear blade pitch, remove the
hairpin cotter from the front trunnion yokes and
loosen the jam nuts (Figure 73).
Figure 73 Z_F2R.TIF
2. Rotate the yokes on the rods to change the
adjustment. To raise the front of the mower,
tighten the yokes (shorten the rods). To lower the
front of the mower, loosen the yokes (lengthen the
rods).
3. After adjusting both trunnion rod yokes evenly,
secure the yokes with the hairpin cotters. Check
the front-to-rear pitch again. Continue adjusting
the yokes until the front blade tip is within
specification.
4. When the front-to-rear blade pitch is correct,
tighten the jam nuts.
5. Recheck the side-to-side leveling and correct if
necessary.
6. If the mower required substantial changes, check
the anti-scalp rollers and re adjust if necessary.
Adjusting Blade Tracking
On mowers with multiple blades, not only do the blades
need to be a minimum of 1/8 inch up from the bottom
edge of the housing, but they must also line up where
the tips come together. Take the two blade tips and
point them towards each other. They must be within
1/8-3/16 inch of level with each other, or both must be
the same distance from the blade to the ground
(Figure 74).
Figure 74 trclevel.TIF
An alternate way to check this is to remove the mower
housing and turn it over. Remove the blades and lay a
straight edge on two blade saddles (Figure 75). It
should lie flat. If not, either the spindle or the housing
where the spindle mounts may be bent.
Figure 75 altbltrk.TIF
Yet another way to check this with the blades attached
is to align the blades (two blades at a time on three
blade mowers), then run a string across the cutting tips
of the blades. The string should be straight. If it is not,
the blade or spindle could be bent.
If the saddles or blades do not line up and the spindles
are not bent, a shim between the spindle housing and
the mower housing may help align them. Loosen the
spindle to mower housing bolts and insert shim
washers until the saddles are in line. Then if you used
washers to shim the spindle housing, remove the bolt
and reassemble through the washer to secure it.
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2. Hairpin cotter
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