Flywheel Inspection Procedure

IMPORTANT:
The minimum flywheel thickness is 2.25 mm (1.11 in.). If the flywheel is less than 2.25 mm (1.11 in.) in thickness and the clutch disc is being replaced with the long travel damper disc (P/N 21120564), it is necessary to replace the flywheel with chamfered flywheel (P/N 21120535).

1. Using a micrometer, measure flywheel thickness in three places around the circumference of the flywheel. All measurements must be made at the same distance in from the edge of the flywheel and at equal distances from each other.

Minimum Flywheel Thickness:

28.25 mm (1.11 in.)

^ If flywheel thickness is not within specification, replace the flywheel.

^ If flywheel thickness is within specification, proceed to next step.





2. Inspect the flywheel ring gear for wear or damage to the teeth.

^ If the flywheel ring gear is damaged, replace the flywheel.

^ If the flywheel ring gear is not damaged, proceed to next step.

3. Check flywheel clutch-disc-contact surface for corrosion, chatter marks, scoring, cracking or overheating (indicated by blue discoloration).

IMPORTANT:
Random black spots on the friction surface of the flywheel are normal.

^ If any of these conditions exist, resurface flywheel. (Do not resurface flywheel below the minimum thickness specification of 28.25 mm [1.11 in.].)

^ If none of these conditions exist, proceed to next step.





4. Using a dial indicator, measure flywheel runout. Push the crankshaft forward to take up thrust bearing clearance. Measure the runout at a diameter just inside the pressure plate bolt holes for at least two revolutions.

Maximum Runout: 0.15 mm (0.006 in.)

^ If the flywheel runout is not within specification, resurface flywheel. (Do not resurface flywheel below the minimum thickness specification of 2.25 mm [1.11 in.].)

^ If the flywheel runout is within specification, proceed to next step.





5. Using a straight edge, check the flywheel for warpage.

Maximum Warpage: 0.15 mm (0.006 in.)

^ If the flywheel warpage 15 not within specification, resurface fly)wheel. (Do not resurface flywheel below the minimum thickness specification of 2.25 mm [11.1 in.].)

^ If the flywheel warpage is within specification, proceed to next step.





6. Inspect inside edge of friction surface toward center of flywheel for a chamfer.

^ If flywheel does not have a chamfer, then a chamfer must be machined into flywheel. Refer to the "Flywheel Chamfering" procedure listed in this bulletin.

^ If flywheel does have a chamfer and all other inspection procedures are within specification with no flywheel damage evident, then flywheel does not need to be replaced.