"Crankwalk" as you guys call it is the lateral movement of the crankshaft, all engines have a set amount of crankshaft endplay, this is controlled by two methods, one of the crankshaft bearings has a lip on it, this is called the thrust bearing, this thrust bearing is machined along with the crankshaft journal to a specified dimension yielding a thrust bearing clearance, once this bearing or crank journal wears, the engine must be torn down and remachined along with bearing replacement.
The other method is is by shimming such as on old Beetle engines and Porsche engines, the thrust bearing is right behind the flywheel, shims are stacked between the flywheel and bearing until the correct clearance is obtained. (In the Porsche's case .0055 is ideal)