Quantum Physics
Fatal traffic accidents involving minibus taxis are a common occurrence in
South Africa today, and many of these accidents are caused by vehicles that
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are not in roadworthy condition. It is relatively easy to identify these vehicles,
merely by a rudimentary inspection. But there are instances where vehicles may
be roadworthy according to the letter of the law, but in actual fact their passengers’ safety is compromised by
inferior quality components, or the incorrect application or identification of parts.
O
ne such example of an incorrect
application is that when an OEM
specifies a specific type of wheel
bearing for a vehicle, and another type of
wheel bearing is used. Most of the time
not through a lack of concern for safety
by the parts reseller or parts fitter,
but in many cases because of a lack
of specific knowledge. The correct
type of wheel bearing for vehicles
that carry heavy loads is a tapered
roller bearing, and not a ball bearing
assembly. This is why OEM’s specify
a tapered roller bearing, but often
not even experienced technicians
may be aware of this, and even
with this knowledge it is difficult to
spot the difference through a casual
visual inspection.
The reason for this type of
application is because the tapered
roller bearing is capable of carrying
more load than the ball bearing type.
This comes from the engineers and
designers’ knowledge that tapered roller
bearing having more points of contact (a
line of contact versus point contact) and
thus being more suitable for a vehicle
➲ Accidents such as these are commonplace,
the causes of which are numerous
that carries heavy loads. While the ball
bearing type may be suitable for passenger
vehicles which carry lighter loads, this type
of bearing is not suitable for the vehicles
designed for passenger carrying abilities.
Thus, using the incorrect bearing type for
passenger carrying vehicles will
compromise passenger safety
as the risk of bearing failure
is increased. In addition, the
longevity of these unsuitable ball
bearing type wheel bearings will
be reduced.
Motorists and workshops are
advised to be mindful of the
differences and are encouraged to
only buy bearings from reputable
distributors. Since the visual
differences are hard to spot from
the outside it is recommended
that buyers ask for the correct
type, and to insist on reputable
brands that carry a quality guarantee.
Spot the difference:
➲ Ball bearing type – unsuitable for the Toyota Quantum,
as it cannot match the abilities of the tapered roller bearing type
when it comes to carrying the specified load, and the longevity
of the bearing is reduced
➲ Tapered roller bearing type – suitable for the
Toyota Quantum, because the taper angles allow the
bearing to handle a combination of radial and thrust
loads. The steeper the cup angle, the greater the ability of
the tapered roller bearing to handle thrust loads
For more information on SKF driveline tools, contact Richard Pinard on 011 974 1444, or email richard@tcauto.co.za