Nobody really knows what causes the crankwalk specifically, allot of ideas though.

For some reason the thrust bearings on some of the 4G63's wear excessively, regardless of which pressure plate you are using.

They just keep wearing and hammering the thrust bearing surface until eventually the engine starts stalling, making weird noises, crank takes out the crank angle sensor, clutch pedal sticking to floor after being depressed.

It's not an issue with the thrust bearings as many people have rolled in new bearings only to have it happen again. Others have rebuilt their same short block only have the thrust bearing fail again.

The best cure is to get rid of the problem all together, the short block.