NHTSA Complaint #11522814 — 2018 PETERBILT 579

Front axle begins popping and making metal to metal noises when hitting bumps and or turning. We took it to the shop and they found the nuts to the U-bolts that hold the leaf springs to the front axle had begun backing off and were out of torque spec. Upon receiving the truck back the front end no longer made this noise. Approximately 8 months later we are hearing the same metal on metal and popping noises that we heard previously. We have also noticed similar year Peterbilt 579's with this same noise and popping so this isn't specific to our vehicle.