The National Highway Traffic Safety Administration opened an investigation into the issue after receiving over a dozen complaints about the lower ball-joints, some of which allege that the control arms on the CX-9 would separate, sending the vehicle out of control.
Mazda traced the failures to water getting past the rubber boot and onto the ball joint. In 2013, a revised boot was added to the CX-9 to prevent this from happening, but a recall of vehicles with the defective boot never occured. This is because Mazda said that the problem was a maintenance issue after realizing that a loud noise would be exhibited for several years before total failure of the ball joint.
Now, under pressure from NHTSA, Mazda says that “the failure might occur without customer’s noticing unusual noise because some VOQs [complaints] showed that a ball joint fell out suddenly.”
The recall, which affects vehicles from 2007 to 2014 model year, will prioritize vehicles in the “salt belt,” as they are more susceptible to the failure.