One of the more common sources of noise from the rear of a guest’s Toyota or Lexus is a failing rear swaybar bushing, particularly as the vehicle ages. Likened to a “clunk” or a “thud”, the noise comes from extra play in the swaybar’s rubber mounting bushings.
Used to control the lean of the vehicle by linking both sides of the suspension together, the swaybar is secured to the body of the vehicle through small brackets and rubber bushings. As they age, the rubber of the bushings begins to break down and lose grip, the resulting friction and twisting resulting in wear of the rubber’s contact surface. Below is a photo of the horizontal wear pattern of swaybar bushing that was causing an abnormal noise from the rear of a 2007 Lexus ES350:
While the bushing only allowed for a few millimeters of play, the noise was enough for concern and warranted replacement. Addressing this noise concern early saved the guest potential headaches resulting from complete bushing failure and metal on metal contact.