2009 Scion xD Suspension Problems

Drove car and heard loud noise issuing from the passenger side rear. Upon viewing the wheel was angled in at the top. After removing the wheel I found the rear crossmember subframe axle had a complete break in the weld holding the angle from the straight part of the beam to the wheel and suspension plate. After going online to see if similar issues happen on the same side of the vehicle, I found many reports of weld failures on the same side at the same joint. This is an EXTREMELY dangerous weld failure--if it had happened during highway travel the potential for catastrophic injury or death is high, in my opinion. Please investigate other reports to the NTSB about this make and model, and please search model years on or about 2007-2012 as other scion owners have had the same issue. This is a one owner car, we purchased it new in 2009. The opposite weld is also showing signs of stress, but not broken or cracked.

A major safety structural defect has developed in the rear axle beam. About 50 percent of the welds failed where the passenger side swing arm attaches to the rest of the axle. The lack of support ended up creating about a three inch stress crack across the width of the swing arm tube. This could have led to a complete failure of the swing arm, had I not found the problem. Had this failure occurred on the highway, it might have caused a serious accident. A month prior I started hearing a pop from the rear of the car each time I would back out of the driveway and the first time I went forward. I crawled under the car within about two weeks and checked things over but found nothing. I thought it might have been a coil spring shifting in its seat or a shock absorber with an internal problem. The noise continued and was getting a bit louder each time it occurred. I ended up lifting the back of the car and pulling the rear wheels. I first found the stress crack across the swing arm tube. Upon further inspection, I realized a portion of the welds had failed. The car is 14 years old and has 159k miles. There is rust that is contributing to the deterioration of the connection, yet the design of the swing arm and its connections seem as though they are barely sufficient when it was new. The design of the swing arm connections does not appear sufficient to be exposed to normal wear and tear of winter driving. In searching for a replacement part, this same exact swing arm is also used on the Toyota Prius C and a Yaris model. So this issue could be occurring on those models as well.