6 months after replacement on my 2009 Silverado, left and right lower ball joints failed, all other replacement suspension parts work fine Parts replacement guarantee. will keep updating. ***** Money back for defective parts within 5 minutes. Send me a refund, allowable time for parts delivery. (ac delco) parts .install.sent return level for me to send back defective parts. It took 5 minutes of my time and Amazon did their best to fix the issue within minutes