John Deere CD4039DF008 - Manual (Page 50)

Maintenance/500 hours
DPSG,CD03523,31 –19–12JUL99–1/1
CHECKING BELT (300-SERIES ENGINES)
CD30644
–UN–04MAY98
CD30645
–UN–04MAY98
CD30646
–UN–04MAY98
1. Inspect belt for cracks, fraying, or stretched out areas.
Replace as necessary.
2. Check belt tension using one of following methods:
a) Use of JDG529 Tension Gauge (A)
Belt tension—Specification
New belt 578—622 N (130—140 lb-force) ..................................................
Used belt 378—423 N (85—94 lb-force) ....................................................
NOTE: Belt is considered used after 10 minutes of
operation.
b) Use of tension tester (B) and straight edge (C)
A 89 N (20 lb) force applied halfway between pulleys
should deflect belt by 19 mm (0.75 in.).
3. If adjustment is necessary, loosen alternator nuts (D)
and (E). Pull alternator frame outward until belt is
correctly tensioned.
IMPORTANT: Do not pry against the alternator rear
frame. Do not tighten or loosen belts
while they are hot.
4. Tighten alternator bracket nuts firmly.
5. Run engine for 10 minutes then recheck belt tension.
30-4
112699
PN=50