MacDon 974 - Sickle Drive Belt Tension

Form # 147083 Issue 01/07
51
MAINTENANCE/SERVICE
SICKLE AND SICKLE DRIVE
(continued)
Sickle Drive Belt Tension
Check sickle drive belt tension after a 5 hour run-in
period and every 100 hours thereafter.
IMPORTANT: To prolong belt and drive life, do not
over-tighten belt. Operate at minimum tension required
to prevent slipping or excessive belt whip. When
installing a new belt, never pry belt over pulley. Loosen
adjusting device sufficiently to allow easy installation.
To adjust:
1. Loosen nut (A).
2. Turn nut (B) to move idler pulley up or down
(depending on drive configuration) to tighten belt
until a force of 18 lbs. (80 N) deflects belt 3/4 inch
(20 mm) at mid-span.
3. Tighten nut (A).
4. Re-adjust tension of a new belt after a short run-in
period, (about 5 hours).
NOTE: To remove belt, back off idler pulley and
remove bolt-on panel in left end sheet at wobble box.
Turn belt on edge and work it up and over pulley hub
as shown.
A
B
SICKLE DRIVE BELT TENSION ADJUSTMENT
COMBINE CONFIGURATION SHOWN
REMOVING SICKLE DRIVE BELT