1. Measure the wear of the diaphragm spring fingers.
Depth
0.6 mm {0.024 in} max.

2. Measure the flatness of the pressure plate with a straight edge and a feeler gauge.
Maximum clearance 0.5 mm {0.020 in}

3. When checking the diaphragm spring fingers, mount a dial indicator on the cylinder block.
4. Rotate the flywheel and check for misaligned diaphragm spring fingers.
Misalignment
0.6 mm {0.024 in} max.

Clutch unit removal/installation
Clutch disc inspectionMazda 6 Service Manual: Variable intake-air system (vis) control solenoid valve inspection (l3)
1. Remove the VIS control solenoid valve. (See INTAKE-AIR SYSTEM
REMOVAL/INSTALLATION.)
2. Inspect airflow between the ports under the following conditions.
If not as specified, replace the VIS control solenoid valve.
If as specified, carry out the Circuit Open/Short Inspection.
Circ ...
Mazda 6 Service Manual: Dtc c1145, c1155, c1165, c1175
Caution
When attaching the tester lead to the DSC HU/CM connector the SST
(49 G066 004) must be used.
Diagnostic procedure
...