Mazda MX-5 Miata Sport 2007 Manual page 712

Fig. 26: Measuring Flatness Of Pressure Plate With Straight Edge & Feeler Gauge
Courtesy of MAZDA MOTORS CORP.
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.
If it exceeds the maximum specification, replace the clutch cover.

Clutch cover maximum height difference
1.0 mm {0.039 in}
2007 Mazda MX-5 Miata Sport
2007 TRANSMISSION Clutch - MX-5 Miata