it down till you are satisfied you have it tight. Then drive it back
again and then with your fist drive the key down as far as you can. You
may consider this a peculiar kind of a hammer, but your boxes will
rarely ever heat after being keyed in this manner.

KNOCK IN ENGINES

What makes an engine knock or pound? A loose pillow block box is a good
"knocker." The pillow block is a box next crank or disc wheel. This box
is usually fitted with set bolts and jam nuts. You must also be careful
not to set this up too tight, remembering always that a box when too
tight begins to heat and this expands the journal, causing greater
friction. A slight turn of a set bolt one way or the other may be
sufficient to cool a box that may be running hot, or to heat one that
may be running cool. A hot box from neglect of oiling can be cooled by
supplying oil, provided it has not already commenced to cut. If it
shows any sign of cutting, the only safe way is to remove the box and
clean it thoroughly.

Loose eccentric yokes will make a knock in an engine, and it may appear
to be in the wrist. You will find packing between the two halves of the
yoke. Take out a thin sheet of this packing, but don't take out too
much, as you are liable then to get them too tight and they may stick
and cause your eccentrics to slip. We will have more to say about the
slipping of the eccentrics.

The piston rod loose in cross-head will make a knock, which also appears
in the wrist, but it is not there. Tighten the piston and you will stop
it. The piston rod may be keyed in cross head, or it may be held in
place by a nut. The key is less liable to get loose, but should it work