A viscous type vibration damper is mounted on the front end of the crankshaft to reduce torsional vibration. See Figure
1.Viscous Vibration Damper
3.Crankshaft Pulley Bolt
Viscous Vibration Damper Mounting
The viscous damper assembly consists of a sealed outer shell, an internal flywheel, and a quantity of highly viscous fluid. See Figure
Viscous Vibration Damper Detail
During operation, the outer shell, which is firmly attached to the crankshaft, turns at the same speed as the crankshaft, its motion being transferred from the crankshaft through the fluid within the shell to the inner ring. Considerable inner ring slippage occurs as power impulses are transmitted through the crankshaft. This is desirable during flywheel acceleration and deceleration, since the damper lessens the vibration amplitude, reducing its effects to a harmless level.
Repair or Replacement of Crankshaft Vibration Damper
To determine if repair is possible or replacement is necessary, perform the following procedure. See Figure
Repair or Replacement of Crankshaft Damper Flowchart
Removal of Crankshaft Vibration Damper
Pre-cleaning is not necessary.
To avoid injury from the projection of tools or other objects that may fall on or behind the vibration damper of an engine, always check and remove these items before starting the engine.
Remove the crankshaft vibration damper as follows:
Remove the six bolts retaining the front engine mount to the block. Remove the front engine mount.
Remove the drive belts from the crankshaft pulley.
Remove the inspection plug in the bottom of the flywheel housing, and install the flywheel lock, J 36375
. See Figure
Thread the center screw of the tooth until the tip of the tool rests between two teeth of the flywheel ring gear.
It may be necessary to bar the engine over so that the center screw of the tool is exactly between two teeth. See Figure
1.Long Handled Breaker
Barring Engine Over
Tighten the knurled knob finger-tight.
Remove two of the eight crankshaft pulley retaining bolts. (Choose two bolts 180 apart.)
Install two guide studs, J 36325
, into the empty bolt holes.
Remove the six remaining bolts.
Carefully remove the crankshaft pulley. The vibration damper may come off with it. If the damper falls, it may be damaged internally.
Do not use a hammer, or pry the damper from the crankshaft. The outer shell may become dented and cause the inner ring to turn at the same speed as the outer shell. This will render the damper ineffective.