Review on ACDelco Professional 45K0187 Adjustable Rear Upper Control Arm Assembly: Premium Quality and Precision Engineering for Optimal Suspension Control by John Chembola

I was able to change the control arms myself on a 2007 Mazda3 in about 2.5 hours, after which it took me 4 cambers ($65) to get the camber angle correct. I used a shop that only does leveling and made sure they are familiar with adjustable control arms. The passenger side took the most time, as there is a box that needs to be unscrewed and pushed aside to remove the existing wishbone. I adjusted the levers to be a quarter inch longer than the stock control levers. My goal was to remove the 2.5 degree negative camber of the stock wishbones (leaning tops of the rear wheels). Negative camber causes rapid wear on the inside of the rear tires. My 45,000 mile tires were removed within 20,000 miles. Not cool. Mazda developed negative camber to provide better cornering traction. More than 98 percent of drivers do not need this additional traction and are simply annoyed by tire wear. These are beefy arms and work much better than cheap camber adjusters that simply replace the top bolt on the stock arms. They tend to break and are very difficult to adjust. That's the real deal.