Thomas PROTOUGH 900 - Page 42

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4. MAINTENANCE
4.4 50 HOUR SERVICE
4.4D Engine Fan Belt
Check the fan belt condition (T90120).
Replace if cracked or chipped. Replace
every 2 years or at 600 hours, whichever
comes first.
Check belt tension half way between the
crankshaft and alternator pulley (S0020).
Correct tension is 7 ~ 9mm deflection @ 98
newtons force. (1/4 ~ 3/8 in. @ 22 lbs.).
T
o adjust the fan belt:
1. Loosen the bolts retaining the alternator
to the engine.
2. Use a pry bar to tension the fan belt and
tighten the top alternator bolt.
3. Check the tension. Repeat steps 1 ~ 2 if
necessary.
4. Tighten bottom alternator bolt.
T
o replace the fan belt:
1. Loosen the alternator bolts.
2. Remove the fan guard.
3. Replace the fan belt, set tension as out-
lined above.
4. Replace the fan guard.
S0020
Alternator pulley
Crankshaft pulley
Measure
deflection
T90120
Engine fan belt