Kimberley KARAVAN 2021, Инструкция по установке, техническому обслуживанию и эксплуатации

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wheel’s center section, likely on the
rear of a wheel spoke).
Checking a hub or wheel bolt pat-
tern can also be performed with the
aid of specialty tools. A bolt circle
reference “disc” (these are available
in all bolt circle sizes) offers multi-
ple hole patterns, with each hole
labeled. Simply drop the disc onto a
hub (or place on the rear mounting
surface of the wheel) until all holes
align. Note which holes align (per
the hole labels). Another method
involves the use of a specialty slid-
ing caliper type tool. Insert the two
tapered pins of the tool into two
adjacent wheel holes and note the
reading on the tool’s gauge.
WHEEL NUT SEAT STYLES
The contact area between the fas-
tener and the wheel is referred to as
the “seat.” This is the surface area
where the fastener actually contacts
the wheel and where clamping pres-
sure is applied when the fastener is
tightened. It is absolutely
vital that the seat style of
the fastener matches the
seat style of the wheel’s
fastener hole entry. The
use of incorrect seat
styles, even though
thread pitch and thread
diameter may be correct,
can easily result in wheel
damage during tighten-
ing, and fastener loosen-
ing during vehicle oper-
ation. If the fasteners
loosen, the wheel will “wobble” as it
moves in relation to the hub.
Eventually, this movement, or play,
will ruin the wheel’s fasteners holes,
resulting in either breaking the
wheel or complete loss of the
tire/wheel assembly.
Do not confuse the style or shape
of the fastener head with the shape
of the fastener’s seat. If a wheel nut
features a radiused head (rounded
head), some folks may call this an
“acorn” nut. However, others will
interpret the term “acorn” as a
radiused or ball-style fastener seat.
Always make sure that you clearly
understand the terminology for seat
styles.
The majority of Toyota wheels
require the use of conical (also
called tapered) seat-style nuts.
However, citing the 1999-2001
Avalon, Camry, Solara and Sienna
models as examples, two different
accessory wheels were offered. Style
1 (wheel part number PT351-
00990) features a conical seat, while
Style 2 (wheel part number PT351-
00991) features a flat-seat (“mag”)
style nut. Each wheel requires the
use of a specific style nut.
Attempting to use a conical-style
nut on a wheel that features flat
seats (or using a flat-seat nut on a
wheel that features conical seats)
will result in both wheel damage
and certain loosening.
AN EXPLANATION OF
WHEEL NUT SEAT STYLES
The most commonly employed
seat styles include conical, radius
and flat (“mag”). These terms refer
to the shape of the seat (where the
INSTALLING ALLOY WHEELS
8
Two types of wheel nuts are used with Toyota wheels. Some alloy
wheels use shank type (mag) wheel nuts that feature flat mounting
bosses. Steel wheels use tapered (conical) wheel nuts. The two
styles are not interchangeable.
This handy caliper-style tool can be used to
quickly determine bolt circle. Insert both pins
into adjacent holes and read the gauge.
Wheel
Wheel
Axle hub
Axle hub
Clearance
Wheel nut (taper point-type)
Wheel nut (flat point-type)
fastener contacts the entry of the
fastener hole in the wheel.
CONICAL
Conical seats are also called
“tapered” or “cone” seats. All three
terms refer to a seat that features an
angled seat wall, where the dimen-
sion of the taper is largest at the top,
under the head, and tapers to a
smaller diameter where the angle
meets the rear face of the nut (or
adjacent to the threaded shank on a
wheel bolt). The most common
angle of taper is 60 degrees. The
male taper nestles into a tapered
relief pocket at the fastener hole
entrance.
RADIUS
Radius seats are also called “ball”
seats, with good reason. The rear of
the nut (or base of the head on a
wheel bolt) is rounded into a ball
shape. It’s like a ball that is cut in
half, with only the radius remain-
ing. The male ball seat fastener con-
tacts the wheel’s female radiused
ball relief.
MAG (FLAT SEAT)
The term “mag” refers to a fasten-
er that features a flat contact at the
wheel (usually including a thick flat
washer). The generic term “mag” is
a holdover from the early days of
custom wheels, when magnesium
was sometimes used to make light-
weight racing wheels. The mag style
nut also features a smooth outer-
walled shank that serves to help
center the wheel (the shank drops
through the wheel hole, serving as a
guide pin to center the wheel’s hole
over the hub’s threaded stud). The
shank length varies depending on
wheel thickness and stud length.
When using a capped nut (where
the female threaded hole does not
pass all the way through the nut),
it’s important to pay attention to
thread engagement length.
FASTENER TORQUE
When tightening any wheel fas-
teners, we need to consider the
degree of tightening in order to
achieve proper clamping load. In
addition, we need to consider the
tightening sequence, or pattern, to
assure that clamping loads are even-
ly distributed across the hub contact
area.
Threaded fasteners, by design, are
intended to stretch slightly when
fully tightened to specification. This
T
O Y O TA’ S
S
U P P O R T
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U T O M O T I V E
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E PA I R
INSTALLING ALLOY WHEELS
9
Shown here are two conical/tapered nuts (two at left); and two ball/radius fasteners at the right. Note that
the two conical nuts feature different engagement lengths. The nut at the far left terminates at the bottom
of the tapered seat while the nut to its right features a slight extension below the conical seat area. The
extended nut (second from left) may be required for a thicker alloy wheel, in order to achieve proper thread
engagement to the stud. Pay strict attention to both seat style and proper thread engagement!