Engine Maintenance (Rev. 04/03)
54
Engine/Compressor/Jackshaft /Belt Tension/
Adjustments
1. Place the engine/compressor belt in the idler pulley.
Make sure the belt is also placed in the engine pulley
and the compressor pulley.
2. Turn the sprocket with a 7/8 in. wrench to tension the
belt. Tighten the pulley bolt with a 3/4 in. wrench when
the belt is at the proper tension. Use one
of following
methods to check (or set) the belt tension.
a. The belt tension should be set at a reading of 70 to
80 on the Thermo King Belt Tension Gauge P/N
204-427.
b. The belt should deflect 1/2 in. (13 mm) at the cen-
ter of the longest (lower) span.
Idler Assembly
c. Use a 7/8 in. crow’s foot attached to a 3/8 in.
torque wrench to turn the sprocket and obtain a
reading of 40 in-lb (4.5 N•m) on the torque wrench
for used belts and 45 in-lb (5.0 N•m) for new belts.
Tighten the pulley bolt while holding the sprocket
in this position. When using this procedure, the
pulley bolt must at first be loose enough to allow
the sprocket to rotate freely. If not, the reading on
the torque wrench will not produce the proper belt
tension.
3. Place the compressor/evaporator fan/alternator belt in
the compressor pulley and check to see that it is cen-
tered in the slot on the left side of the idler bracket. If
not, adjust the position of the left evaporator fan pulley
on the fan shaft so the belt is centered in the slot. Adjust
the compressor/evaporator fan/alternator belt to the
proper tension after it is centered in the slot.
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