Wayne Hoskin Wrote:
> So I am presuming that each time crank pins are
> 'quartered' a little material is taken off and
> thus the pin gets smaller, so new bushes are
> machined up to suit the smaller crank pin size?
Correct. We generally get 2 to 4 seasons out of a set of bushings and they were due for replacement this time anyway.
> If so, how much smaller or how much material had
> to be removed in this particular operation?
A fair amount, in this case. The pins were about 1/2 degree out of position. The largest error turned out to be in one counterweight that has a slightly off location pin bore introduced years ago, most likely during a shopping by the D&RGW. Between that and cleaning up some normal wear, we ended up taking an average of about .140 off of each pin. Fortunately, the pins were in good shape, so we had plenty of material available to safely make the adjustment. When it is eventually time to renew that crank pin the best solution will be to re-bore the hole in the counterweight to the correct location. Under normal conditions, that is probably something like 20+ years in the future.