4Piston | Diamond Claw Crank Lock | Honda Civic Type R | FK2/FK8 2.0T K20C1 | 2015+DESCRIPTION 4P Diamond Claw flywheel surface lock helps to prevent flywheel bolts from backing out of the crankshaft in high rpm applications where vibrations and harmonics often cause welding of the flywheel to the crank. In the event that the flywheel does become loose and start to vibrate against the crank, this surface lock can help to protect the crank and prevent damage. Diamond Claw Surface Locks have successfully eliminated fretting (surface