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130 badly worn, the old brass may be re-metalled with white metal. The centres are marked off when the boxes are in place on the engine, and the boxes are then sent to the machine for re-boring. The centres must be properly located so that the distance apart of the different axles is exactly correct.

The Motion, etc. Connecting and coupling rods are examined for flaws, and if any are found in the bodies the rods are at once condemned. Usually flaws in connecting rods occur in the “big-end” straps at the corners and bolt holes. These straps being smaller independent pieces are not so expensive to renew. The rods are also tested for straightness with a straight-edge. The straps will require filing up and perhaps closing a little at the jaws, and the brasses, frequently new, must be a perfect fit in the straps, and be made perfectly square with the rods. The brasses having been fitted and bolted up the ends are placed on the rods and the length between centres of the big and small ends on each rod is trammelled to the dimensions shown on the drawings. The centres are marked and the ends sent to the machine to be bored out to the size of the crank pin journal, to which they are then fitted. Coupling rods are more easily repaired by having new white metal circular bushes pressed into the solid ends of the rods. This work is done in a small hydraulic press.

Slide bars are re-ground on a grinding machine,