Hyundai Sonata challenges rebuilders, 199-Later If you have ever rebuilt a late model (1999 and newer) Sonata only to have it returned with converter clutch failure, this story may help solve your problem.
The type friction material used on the OEM clutch is very aggressive in design. Neither the industry standard red nor black liner seems to deliver the correct clutch application. Without getting into physics and explaining the reason behind this repair, we will jump right to it.
Use the Sonnax black paper liner, .040, and bond it to the piston. Fixture the piston in the lathe, and machine the liner so that only one half inch on liner remains. This increases the pressure per square inch on the liner as compared to the wider liner and all should be well. The clutch feel is more desirable without suffering performance.
Found in issue April 2004