2.22. MOUNTING WHEELS
For mounting wheels on an axle two basic kinds of wheel-mounting presses are used: the single-end and
the double-end. The designs of each may vary as do the amounts of pressure each is capable of developing.
However, the operating principle is the same for both: the wheel is held firmly in place and a pressured ram
forces the axle into the wheel bore. The only difference in the two types of presses is the advantage the double-
end press has over the single end. The mounted wheel and axle must be completely removed from the single-
end press, turned around, and replaced in the press before the second wheel can be mounted. This procedure is
not necessary with the double-end press which can press the axle from both ends. One wheel is mounted, the
second wheel is placed on the opposite end of the axle, and the ram forces the axle from the end opposite the
unmounted wheel. This type of press saves time and labor.
The amount of pressure the presses can develop varies from 200 to 600 tons. The reason for the great
variation is that different pressures are needed for mounting wheels and for dismounting. Wheel presses used
for mounting should have a capacity from 200 to 300 tons; those used for dismounting need capacities of 400 to
600 tons. Whenever possible, two separate presses should be used; however, if you have only one press, it
should have the higher pressure capacity. Each press should have both a dial pressure gage and a pressure
recording gage. The latter should be mounted separate from the press to protect it from the shock of the
pressing operation. Both gages should be checked frequently to insure that they agree with each other. Master
gages are used to make the check. If the same press is used for both mounting and dismounting, the gages
should be disconnected before applying the higher dismounting pressures. Table V shows the maximum and
minimum pressures in tons that are required to mount steel wheels on each axle classification.
2.23. PROCEDURES FOR WHEEL MOUNTING
The process of properly mounting wheels on axles is a technical business requiring highly skilled men.
The complete process is too lengthy and complex to be included in this text; however, you should be familiar
with some of the important procedures of wheel mounting. The following subparagraphs discuss journal
protection, cleaning of bores and wheel seats, positioning high spots on flanges, centering wheels, and checking