Kimberley KARAVAN 2021, Installation, Maintenance & Operating Manual

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108 ©2021 Kimberley Kampers Manufacturing Pty Ltd
creates a preload, which is what
serves to clamp the wheel securely
to the hub. If undertightened, the
nut (or bolt) can gradually loosen,
and we all know the consequences
of that. If overtightened, the stud or
bolt can exceed its “elastic” range,
and can permanently stretch
(fatigue), which destroys its ability
to provide clamping load. If this
happens, the stud or bolt can either
loosen on its own or can break dur-
ing operation. Especially when deal-
ing with today’s lightweight alloy
wheels and sometimes light (and
thin) rotor mounting faces, severe
wheel vibrations under braking can
occur if wheels are improperly or
unevenly tightened.
REASONS TO NOT USE
AN IMPACT GUN ON
ALLOY WHEELS
An impact gun (especially when
installing wheels) can wreak havoc
on alloy wheels. Fastener damage
can occur as a result of a socket
banging against a nut’s chrome plat-
ing. If aftermarket spline-drive
“tuner” nuts are used, the narrow
splines can be burred. Probably the
biggest area of concern is inaccurate
and/or excessive clamping loads,
which can distort the wheel and its
mated hub/rotor, leading to vibra-
tion complaints. Additional wheel
cosmetic damage can result if sock-
et-to-fastener recess is minimal, or
if a thick-walled socket is used that
minimizes clearance, the outer wall
of the socket can abrade against the
wheel’s nut recess.
If the socket is dirty, abrasive
damage to both the fastener and
wheel are possible. In addition,
excessive tightening can cause the
nut or bolt seat to pound into the
aluminum wheel’s seat pocket,
displacing the aluminum (goug-
ing/deforming the alloy). This can
lead to eventual fastener loosening,
since the seat base integrity has
been deformed or reduced.
Excessive tightening can also stress
the wheel stud, permanently
stretching the threaded shank
INSTALLING ALLOY WHEELS
10
While the use of a torque wrench is preferred for tightening an alloy
wheel, if an impact gun must be used, be sure to employ torque
sticks, which feature a pre-set torsional limiting range to prevent
over-tightening.
Any busy shop should have their torque wrenches periodically re-
calibrated in order to maintain accuracy and consistency.