Figure 6 CONNECTING ROD ALIGNER

Slide the rod along the mandrel until the dowels of the jig just touch the surface of the faceplate. If the dowels do not touch the plate, then the rod is misaligned.

The rod should be checked for bend and then for twist. To do this, the jig is mounted in two different positions on the piston pin:

1. with the dowels verticals

This will check for bend in the rod. If the rod is straight, both vertical dowels will be in contact with the faceplate If only one dowel contacts the faceplate, then the rod is bent.

This will check for twist in the rod. If the rod is true, and not twisted, both horizontal dowels will be in contact with the faceplate. If only one dowel contacts the faceplate (B), then the rod is twisted. The allowable misalignment, for both bend and twist is around 0.10mm. This is checked with feeler gauges between the dowels and the faceplate.

Connecting rods that are slightly misaligned can be straightened in a special jig designed for this purpose. A press or bending bar can also be used. When straightening a connecting rod, it should be bent a little beyond the point where it is straight and then bent back to obtain correct alignment. This relieves the stress in the rod and it is less likely to tend to take up a permanent set and, for this reason, doubtful or badly misaligned rods should be replaced.