linseed oil. This lubrication prevents scoring of the mounting surfaces as the wheel is started onto the wheel
seat. The correct blend of the lubricant is 12 pounds of white lead thoroughly mixed with 1 gallon of boiled
linseed oil. The mixture should be made at least 12 hours before it is to be used. Only a few days supply should
be mixed at a time because the linseed oil tends to dry allowing the mixture to thicken. Improper wheel fits can
result when the lubricant is too thick. It is important that dirt and grit be prevented from getting into the mixture
or on the brush used to apply it. This would nullify the cleaning process and cause scratches on the mounting
surfaces of wheel seats and bores.
c. Matching high spots. In normal use, the flanges of wheels develop high spots. These spots may not be
high enough to condemn the wheel; however, when they are remounted on an axle, the high spots should be
marked and placed opposite the low spots on the mating wheel. If high spots on both wheels were mounted in
the same place, they would cause a bumpy roll.
d. Centering wheels. When wheels are being mounted, they should be exactly centered on the axle both
during the mounting process and at its completion. If a wheel is not properly centered during mounting, the
bore of the wheel will scratch and gouge the wheel seat. If this is not observed and corrected and the wheel is
mounted off center, excessive flange wear will occur on the wheels and overheated journals will result. Several
gages have been developed to determine if wheels are centered properly.
e. Checking gage. When two wheels are mounted upon an axle, they must be in gage--the exact distance to
match the gage of the rail line over which they are to be operated. In the United States, all rail lines are standard
gage, 56 1/2 inches. The gage of a rail line is the distance between the top inside of the heads of the rails. Since
the wheel treads ride the top of the heads of the rails and the wheel flanges contact the inside of the heads, you
can see that it is a must for wheels to be mounted to proper gage. For example, if you were mounting wheels for
a standard-gage rail line, and you mounted two wheels on an axle so that the flanges were 59 1/2 inches apart,
they obviously would not fit your railroad.
Several gages are used to check the gage of wheels on axles; figure 2.27 gives the dimensions of a check
gage. When this gage is used, one wheel should be mounted and the gage placed on the mounted wheel and
held over the other wheel while it is slowly being pressed onto the wheel seat. When the gage fits over the
flange and rests on the tread of the wheel, as illustrated in figure 2.27, the