John Deere stx38 - Manual (Page 305)

3/21/97
8 - 19
MISCELLANEOUS MOWER DECKS
MOWER BLADE ADJUSTMENT
Reason:
To insure mower deck blades cut evenly.
Procedure:
1. Check blade alignment by measuring the
difference in height, from one lower tip to the other
tip.
NOTE: Some mismatch between blades is normal. As
a general rule if the difference between lower
tip of one blade is less than 1/4 inch (6 mm)
different than the lower tip of the other blade, it
will be undetectable. No action is necessary.
The comparison must be made with the tips
rotated and positioned next to each other. The
lower tip of each blade does the cutting, so
compare the lower tips only.
If blade difference is 1/4 inch (6 mm) or more, use the
following procedure to determine cause.
1. Mark the blade tips that are being compared A—B
and C—B.
2. Compare tips A and B of first blade to tip C of the
other blade.
3. If the difference between A and B is greater than
1/8 inch (3 mm):
• Loosen and turn blade on spindle approximately 90
degrees—recheck.
• If difference does not change, blade is not flat—
replace
• If it changes, spindle is bent—replace
4. If the difference between A and B is less than
1/8 inch (3 mm) go to step 5.
5. Compare tips C and D of second blade to tip B of
first blade. If the difference between C and D is
greater than 1/8 inch (3 mm):
• Loosen and turn blade on spindle approximately 90
degrees—recheck.
• If difference does not change, blade is not flat—
replace
• If it changes, spindle is bent—replace
6. If the difference between C and D is less than
1/8 inch (3 mm):
• If the blade and spindle are acceptable, the deck
may be warped or spindle pocket bent. Place a
straight edge across blade from one blade cap
screw to the other. Measure from straight edge to
blade tips to determine which spindle pocket is off.
Install a shim (washer) on the appropriate spindle
side, under 2 of the 4 spindle housing cap screws
to bring blade back to level.
Difference in
blade lower tips
M85800
M85800
C
A
B
D
C
A
B
M85800
M85800
C
B
D