Blue Bird Coachworks 450 LXi, Owner'S Manual

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450 LXi Owner Manual 5-3 Engine Maintenance
Rev. “C”
~ 5-3-21 ~
5-3.21 Crankshaft Vibration Damper - Inspect
Damage to the crankshaft vibration damper or failure of the crankshaft vibration damper can increase torsional vibrations.
This can result in damage to the crankshaft and to other engine components. A damper that is damaged can cause excessive
gear train noise at variable points in the speed range.
The damper is mounted to the crankshaft which is located behind the belt guard on the front of the engine.
5-3.21.1 Visconic Damper
The visconic damper has a weight that is located inside a fl uid fi lled case. The weight moves in the case in order to limit
torsional vibration.
Inspect the damper for evidence of fl uid leaks. If a fl uid leak is found, determine the type of fl uid. The fl uid in the damper is
silicone. Silicone has the following characteristics: transparent, viscous, smooth, and diffi cult to remove from surfaces.
If the fl uid leak is oil, inspect the crankshaft seals for leaks. If a leak is observed, replace the crankshaft seals.
Inspect the damper and repair or replacement the damper for any of the following reasons:
The damper is dented, cracked, or leaking.
The paint on the damper is discolored from heat.
The engine has had a failure because of broken crankshaft.
Analysis of the oil has revealed that the front main bearing is badly worn.
There is a large amount of gear train wear that is not caused by a lack of oil.
Consult your Caterpillar dealer for information about damper replacement.
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5-3.22 Cylinder Head Grounding Stud - Inspect/Clean/Tighten
Inspect the OEM vehicle wiring harness for the following conditions:
Connections that are loose or disconnected
Mounting hardware that is missing
Insulation that is chafed or cut
Wires that are bare
The cylinder head grounding stud must have a wire ground to the battery.
Tighten the cylinder head grounding stud at every oil change. Ground wires and
straps should be combined at engine grounds. All grounds should be tight and
free of corrosion.
Clean the cylinder head grounding stud and the terminals for the cylinder
head ground strap with a clean cloth.
If the connections are corroded, clean the connections with a solution of
baking soda and water.
Keep the cylinder head grounding stud and the strap clean and coated with
MPGM grease or petroleum jelly.
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(1) Cylinder head grounding stud