Harmonic balancer with one weight mounted on the outside and inside of a crankshaft pulley for high engine speed vibration reduction.

Pulley that may be part of a harmonic balancer or bolted to the front of it. It operates belts for the alternator, water pump, air conditioning compressor, and other units.

A thin, stamped steel or cast aluminum cover that encloses the timing chain or gear mechanism. It blocks dirt and debris while preventing oil leakage.

Calibrating mark on timing gears or other timing devices. They are used to set engine timing.