Drivelines and axlesFWD axlesConstant velocity jointsCV bootsCV serviceRWD drive shaftsU-jointsU-joint serviceSlide 9Drivelines and axlesFWD axlesDrive axles for FWD commonly called half shaftsHalf shafts allow wheels to turn and have suspension movements–Half shafts consist of inner CV joint, axle shaft and outer CV joint–Most half shafts are unequal length causing torque steerMost use a sealed front wheel bearingConstant velocity jointsCV joints deliver uniform torque through wide range of anglesInner joints must be plunge typeOuter joints usually have wide range of angles and do not plunge (Rzeppa)Joints must operate in a sealed and clean environmentCV bootsBoots must seal joint and greaseCommon failure point on outer jointAxle and joints must be removed to replace boot and greaseOnly solid boots should be usedMay need special tools for clampsCV serviceNormally a failed joint will cause noise–Clicking joint on turns is usually outer CV–Vibration during accel/decel and /or clunk usually inner CVRunning wheels off of ground can damage jointsMoisture / dirt in joint from ruptured boot is death to the jointRWD drive shaftsDrive shaft connects transmission to rear axleMay be called propeller shaftMay be one piece or two piece if needed due to anglesWill have at least two u-jointsWill have critical balance weightsU-jointsSimilar to CV joints in purpose but not as flexibleU-joint angles must be similar to cancel each otherU-joints must be phased to eliminate vibrationFront yoke of driveline must be able to plunge in and out on transmission output shaftU-joint serviceCan be retained in yoke by outside or inside snap rings Can be retained by injected plasticDefective u-joints will normally cause vibrationsWorn joint may cause clunk on accelMost joints are permanently lubed–Some replacement joints have lube