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Home >> Alfa Romeo >> 2019 >> Giulia Base, AWD >> Repair and Diagnosis >> Drivelines & Axles >> Axle Shafts >> Front HALFSHAFT >> Diagnosis And Testing >> Diagnosis And Testing - Half Shaft >> Vibration At Highway Speeds

Vibration At Highway Speeds

Vibration associated with the Constant Velocity (CV) joints in the halfshafts occur in the 3rd and 6th order (3 or 6 events for each rotation). The inner tripod joint with three pivot axis has three events in each rotation of the halfshaft. This will produce a 3rd order vibration of the wheel rotation speed. The outer CV joint with 6 pivot axis balls has six events in each rotation of the halfshaft. This will produce a 6th order vibration of the wheel rotation speed. A 6th order vibration will create a high pitch sound, like gear noise. Use a vibration analyzer to determine the frequency of the vibration before replacing components.

SYMPTOM POSSIBLE CAUSE REPAIR
Low frequency vibration, matching wheel speed. Wheel balance and runout is OK.
  • Foreign material (plastic bags, organic sinew and road debris) fouling the halfshaft.
  • Clean debris from around halfshaft.
High frequency vibration matching 3rd order wheel speed.
  • Faulty inner tripod joint.
  • Vehicle ride height is modified.
  • Replace halfshaft.
  • Return vehicle to proper ride height.
High pitch whine sound with possible high frequency vibration in the floor matching 6th order wheel speed.
  • Faulty outer CV joint.
  • Vehicle ride height is modified.
  • Replace halfshaft.
  • Return vehicle to proper ride height.