MacDon FD75 OM - Manual (Page 325)

MAINTENANCE AND SERVICING
Adjusting Hold-Downs with Stub Guards
To adjust the clearance between hold-downs and knife for
all stub guards, follow these steps:
1. Check the clearances between the center guard
hold-down (A) and knife section with a feeler gauge.
The clearances should be:
• 0.004–0.016 in. (0.1–0.4 mm) at guide tip (B)
• 0.004–0.040 in. (0.1–1.0 mm) at rear of guide (C)
2. If required, adjust clearances as follows: .
a. Torque nuts (D) to 35 ft·lbf (46 N·m).
b. Turn the three adjuster bolts (E) as required.
c. Torque nuts (D) to 53 ft·lbf (72 N·m).
3. After adjusting all hold-downs, run header at a low
engine speed and listen for noise due to insufficient
clearance.
Insufficient clearance will also result
in overheating of the knife and guards. Re-adjust
as necessary.
Figure 6.110: Stub Guards
A - Hold-Down B - Clearance
C - Clearance D - Nut
E - Adjuster Bolt
6.8.8 Knife Drive Belt
The knife drive box is driven with a V-belt from a hydraulic motor on the header left endsheet. An identical drive
system is used at the opposite end for double knife headers.
Removing Knife Drive Belt (Non-Timed)
This procedure describes the removal of the knife drive belt on single knife headers and double knife headers with
non-timed drives.
NOTE:
Procedure is the same for both sides of a double knife header.
1. Open endshield. Refer to Opening Endshields, page
35 .
2. Loosen the two bolts (A) that secure the motor
assembly to header endsheet.
3. Loosen the belt by turning the tensioning bolt (B)
counterclockwise.
Figure 6.111: Knife Drive
169894 311 Revision A