The sealing rings are synthetic resin with chamfered ends. Check the condition of the sealing rings, and replace them only if they are worn, distorted, or damaged.
For a better fit, squeeze sealing rings together slightly before installing them.

Apply ATF to the new sealing rings, then install them on the secondary shaft.

After installing the sealing rings, verify the following:
The rings are fully seated in the groove.
The rings are not twisted.
The chamfered ends of the rings are properly joined.
Manual Transmission Removal (M/T)
Special Tools Required
Universal Lifting Eyelet 07AAK-SNAA120
1.8 Support Bolt 07AAK-SNAA500
Engine Support Hanger, A and Reds AAR-T1256
*: Reds engine support hanger AAR-T1256 is available th ...
Reporting Safety Defects (U.S. Vehicles)
If you believe that your vehicle has a defect which could cause a crash or could
cause injury or death, you should immediately inform the National Highway Traffic
Safety Administration (NHTSA) in ...
Warm Up TWC Removal/Installation
NOTE: If the warm up TWC is damaged internally, inspect the under-floor TWC
for debris.
Raise the vehicle on a lift.
Remove the bolts (A).
Lower the vehicle.
...