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: Engine tune-up
IGNITION TIMING INSPECTION
Note
Ignition timing is not adjustable.
Ignition timing verification requires WDS or equivalent.
1. Turn off the electrical loads.
2. Warm up the engine as follows.
(1) Start the engine.
(2) Maintain the engine speed at approx. 3,000 rpm until the
cooli ...
Mazda 6 Service Manual: Pcv valve inspection
1. Disconnect the negative battery cable.
2. Remove the intake maniforld.(see INTAKE-AIR SYSTEM REMOVAL/INSTALLATION.)
3. Remove the PCV valve.
4. Blow through the valve and verify that air flows as specified.
If not as specified, replace the PCV valve.
Specification
...