Q: What are the components and symptoms of worn or damaged CV joints and driveaxle shafts?
A: Power is transmitted from the transaxle to the wheels through a pair of axle shafts. The inner end of each axle shaft is splined into the differential side gears. The outer ends of the axle shafts are splined to the axle hubs and locked in place by a large nut. The inner ends of the axle shafts are equipped with sliding constant velocity joints, which are capable of both angular and axial motion. Each inner joint assembly consists of a tripod bearing and a joint housing (outer race) in which the joint is free to slide in and out as the axle shaft moves up and down with the wheel. The joints can be disassembled and cleaned in the event of a boot failure, but if any parts are damaged, the joints must be replaced as a unit. When buying parts for an axle shaft, or a complete replacement axle shaft assembly, make sure you get the correct components. The outer CV joints consist of ball bearings running between an inner race and an outer cage, and are capable of angular but not axial movement. The outer joints should be cleaned, inspected, and repacked, but they cannot be disassembled. If an outer joint is damaged, it must be replaced along with the axle shaft. The boots should be inspected periodically for damage and leaking lubricant. Torn CV joint boots must be replaced immediately or the joints can be damaged. Boot replacement involves removal of the axle shaft. The most common symptom of worn or damaged CV joints, besides lubricant leaks, is a clicking noise in turns, a clunk when accelerating after coasting, and vibration at highway speeds. To check for wear in the CV joints and axle shafts, grasp each axle (one at a time) and rotate it in both directions while holding the CV joint housings, feeling for play indicating worn splines or sloppy CV joints. Also check the axle shafts for cracks, dents, and distortion.
A: Disconnect the cable from the negative terminal of the battery, set the parking brake, and loosen the front wheel lugnuts. Raise vehicle and securely support it on jackstands before removing wheel. Unstake axle shaft/hub nut and remove using a prybar wedged between two of the wheel studs to prevent hub from turning. Tap end of axle shaft with a soft-faced hammer or a hammer and a brass punch to loosen it from hub splines. If axle shaft is stuck, remove brake disc and push it from hub with two-jaw puller. Remove engine splash shields and place a drain pan underneath transaxle to catch any lubricant that may spill out when axle shaft is removed. Remove nuts and bolt securing balljoint to control arm, then pry control arm down to separate components. Pull out on steering knuckle and detach axle shaft from hub, supporting outer end of axle shaft with piece of wire if necessary. Carefully pry inner CV joint out of transaxle. To install, reverse removal procedure, pushing axle shaft sharply in to seat retaining ring on inner CV joint in groove in differential side gear. Tighten new axle shaft/hub nut to torque specifications, then stake collar of nut into groove in axle shaft. Tighten lug nuts to proper torque specifications and check transaxle lubricant, adding if necessary to bring it up to proper level.