MacDon FD75 OM - Manual (Page 323)

MAINTENANCE AND SERVICING
1. Remove the two nuts (A) and bolts that attach guard (B)
and top guide (C) and adjuster bar (D) to cutterbar.
2. Remove guard, poly wear plate (if installed), top
guide (C), and adjuster bar (D).
3. Locate poly wear plate (if applicable), replacement
guard (B), adjuster bar (D), top guide (C), and install
bolts, but do NOT tighten.
IMPORTANT:
Ensure center guard (B) has offset cutting
surfaces. The top guide (C), which is an inverted
normal stub guard, must accommodate the two
overlapping knifes at center guard location on
double-knife header.
Ensure replacements are
correct part.
4. Check and adjust clearance between hold-down and
knife. Refer to
Knife Hold-Downs, page 309 .
Figure 6.107: Stub Guards
A - Nuts B - Center Guard
C - Normal Top Guide D - Adjuster Bar
Knife Hold-Downs
Check daily that knife hold-downs are set to prevent knife sections from lifting off guards, but still permit knife to slide
without binding. If there is obvious evidence that the hold downs are not properly adjusted, check the clearance
between the hold down and knife section with a feeler gauge.
Refer to:
• Adjusting Hold-Downs with Pointed Guards, page 310 or
• Adjusting Hold-Downs with Stub Guards, page 311
NOTE:
Guards should be aligned prior to adjusting hold-downs. See Adjusting Knife Guards, page 305 .
169894 309 Revision A