TM 9-4310-397-14
(a) If using tension gauge (1) do the following:
1. Place gauge on the long part of the belt and take a reading.
NOTE
Belts are considered used after ten minutes of operation.
2. New belt reading for single belt should be 130-140 lb force (578-622N).
3. Used belt reading for single belt should be 85-94 lb force (378-423 N).
(b) If using tension gauge (2) and a straight edge do the following:
1 Place straight edge (3) between pulleys.
2 A 30 lb (130 N) force halfway between the pulleys should deflect the belt 0.50 in (13 mm).
CAUTION
Too little tension causes slippage or slip and grab, causing the belt to break. If the belt does
not break, the slip will cause excessive cover wear, bum spots and overheating. Too much
tension can cause belt heating and excessive stretch, as well as damage to drive components,
such as sheaves and shafts. Excessive tightness will also place heavier loads on the
bearings causing them to fail prematurely.
(3)
If belt needs adjustment, loosen alternator bracket screw (4) and (5).
(4)
Apply outward pressure to alternator front frame until belt tension is correct.
(5)
Tighten screws (4) and (5). Remove tension gauge.
(6)
Start engine and run for ten minutes. Shut engine off.
(7)
Check tension again. If tension is not within specifications, wait ten minutes and adjust for used belt
tension.
(8)
Repeat steps (3) through (7).
b.
Removal.
(1)
Disconnect battery cables per paragraph 4-49.
(2)
Disconnect connector (Figure 4-72, 1).
4-167
