Abstract: A method of determining the projection of the upper end (15) of a cylinder liner (14) above the top surface (13) of a cylinder block structure (10). The cylinder liner (14) is caused to be fully inserted into the cylinder bore (11) by a press ring (32) acting on the upper end of the cylinder liner concurrently with the measurement of its position. The press ring is resiliently forced against the top surface (37) of the cylinder liner by a plurality of pressure springs (35) and a pressure plate (25). The pressure plate is urged into engagement with the cylinder block structure top surface (13) by a holddown bar (26). The measuring system utilizes a gage indicator (20) having a probe which is selectively engaged with the upper surface of the cylinder liner adjacent positions of force transfer between the press ring and cylinder liner. The probe is caused to determine the position of the cylinder block structure upper surface (13) selectively directly or indirectly.

Abstract: Pin bores of excavator forebooms are subjected to impact and side loading, causing wear which eventually leads to wobble of the foreboom. The close tolerance required in reboring such bores has previously necessitated transporting the foreboom to repair shops with large machine tools and jigging capacity for such massive structures. The present invention provides a fixture embodiment (30) adapted to rebore a workpiece (10), such as a foreboom, to within close tolerances in conjunction with an easily portable powered drill or the like. Reboring operations may be performed at any convenient site. Fixture embodiment (30) comprises a guide member (32), a structure (40) for holding the guide member (32) to the workpiece (10) in a precisely positioned relationship, a boring bar (52) and a supporting and aligning structure (70). A method for reboring the workpiece (10) is also disclosed.