Health and safety in motor vehicle repair and associated industries

Figure 33 Demountable rims
Health and Safety
Executive
Figure 31 Two-piece wheel Figure 32 Three-piece wheel
148 Failure of the
locking ring/flange to
seat correctly can lead
to violent separation of
the component parts
of the wheel under
pressure. Carefully
check locking rings and
flanges before refitting
and replace any that are
damaged. Lubricate the
components according
to the manufacturer’s
instructions – do not
hammer into position.
To ensure the loose
components are properly
seated, inflate to no
more than 15 psi with
the fitter outside the likely
explosion trajectory. Final inflation of such assembles should follow the precautions
in paragraphs 142 to 144, except that a bag-type restraint is not designed for this
type of assembly – use a metal cage or frame instead.
Divided wheels
149 Divided wheels consist of two parts bolted together with an outer ring of rim
fasteners, the whole assembly then being bolted to the vehicle hub by an inner ring
of hub studs (see Figures 34 and 35).
150 Loosening the rim fasteners with the tyre under pressure has resulted in violent
separation of rim halves, causing fatal injuries. Loosening the hub studs can have
the same result if there has been damage or unauthorised repair to the wheel.
Sometimes the rim-clamping nuts are painted in a contrasting colour to the rim to
distinguish them.
151 Do not secure the rim-clamping bolts in position by welding the bolt head to
one half of the wheel. This is likely to lead to weakening of the bolt, and if carried
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