1. Remove the upper arm from the vehicle.
2. Inspect for damage, cracks, and bending.

3. Inspect the ball joint rotation torque.
(1) Rotate the ball joint five times.
(2) Measure the rotation torque using a suitable allen socket and a torque wrench.
- If not within the specification, replace the lower arm component.
Rotation torque
1.5 N·m {15.0 kgf·cm, 13.2 in·lbf} max.
Front upper arm removal/installation
Front lower arm (front) removal/installationMazda 6 Service Manual: Rear seat disassembly/assembly
4SD
1. Disassemble in the order indicated in the table.
2. Assemble in the reverse order of disassembly.
5HB
1. Disassemble in the order indicated in the table.
2. Assemble in the reverse order of disassembly.
...
Mazda 6 Service Manual: No.1 while vehicle is in reverse, vehicle locator mark goes forward
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunction. If there
is a problem, check to make sure connectors, terminals and wiri ...