MacDon 4000 Mower Conditioner - Manual (Page 51)

51
MAINTENANCE/SERVICE
KNIFE AND KNIFE DRIVE (continued)
Knife Drive Belt Tension
IMPORTANT: To prolong belt and drive life, do not
over-tighten belt.
To adjust:
1. Loosen nut (A).
2. Back off nut (B).
3. Turn adjuster nut (C) until recommended
tension is reached.
RECOMMENDED TENSION:
New belt - a force of 20 lbs. (90 N) deflects belt 1/4
in. (6 mm) at mid-span.
Used belt - a force of 12 lbs. (55 N) deflects belt
1/4 in. (6 mm) at mid-span.
4. Tighten nuts (A) and (B).
5. Re-adjust tension of a new belt after a short
run-in period, (about 5 hours) to used belt
specifications.
Knife Drive Belt Replacement
To remove belt:
1. Remove shield (D).
2. Scratch an alignment mark on pulley (E) and
yoke plate (F) to maintain roll timing on re-
assembly.
3. Remove three bolts (G) and remove yoke
plate.
4. Slacken the belt as follows:
- loosen nut (A)
- back off nut (C)
- turn nut (B) until nut (A) clears wobble box
pulley
5. Remove belt.
When installing new belt, be sure to:
1. Align marks on pulley and yoke plate.
NOTE: Spline shaft and yoke will mate in one
position only.
2. Tighten three bolts (G) to 70 ft.lbs. (95 N.m).
3. Install shield (D).
4. Properly adjust belt tension. Never pry belt
over pulley.
KNIFE DRIVE BELT
TENSION ADJUSTMENT
C
B
A
KNIFE DRIVE BELT REMOVAL
C
B
A
E
F
G
D