Bushing Basics.pdf - Acura Vigor Club

BUSHING BASICSWorn stabilizer bar mounting bushings may cause a clunk that’s hardto differentiate from a similar noise caused by a bad suspension strut.Check for play here with the vehicle’s weight resting on its wheels.Photos: Sam BellWhat purpose do bushingsserve? The answers fall into threegeneral categories:•They prevent wear to a moreexpensive or less easily replacedpart.•They cushion or absorb someroughness or vibration that wouldotherwise be transmitted to the interiorof the car or its occupants.•They allow a small amount ofmotion, which could not be accommodatedby a rigid joint.Our understanding of the needfor bushings can be improved byconsidering things taken to theirlimits: If, for example, there wereonly a rigid connection betweenthe control arm and the frame,any irregularity in the road surfacewould virtually send us airborne.Yet if the same control armwere connected only by a spring,we would bounce our way downthe road like some low-rider cartooncharacter.Materials SelectionMany different elastomer formulationsare used in OE and aftermarketbushings. A durometer isused to measure the rigidity of thebushing material. Materials with ahigher durometer index are morerigid than those with a lowerdurometer index. But rigidity isnot the only factor that’s consideredby the manufacturer whenselecting bushing materials for agiven application.Bill Beard works on the DanaTech Line, where he dispenses informationand counsel on steeringand suspension service issues. Billstresses the importance of consideringthe surrounding environmentwhen choosing the correctbushing replacement materials.“For example, many Ford radiusrod bushings are exposed tohigh temperatures from nearbyexhaust and to oil spillage due tobeing located more or less beneaththe engine oil filter,” he26 June 2003