Simplify the following text for a Grade 6 native English-speaking person.
Original: However , crankshaft torsional vibration , present to some degree in all engines , is sufficient to require the use of a harmonic damper at the accessory end of the crankshaft .
Simplified: Crankshaft vibration is present in all engines . The use of a harmonic damper is needed at the end of the crankshaft .