change wheel GMC SIERRA 2021 Owner's Guide

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Driving and Operating 269
6. Guidance Lines/Hitch Guidance
Guidance Lines displays available
guidelines, including Standard and
Hitch Guidance. A grayed-out icon
indicates that guidelines are not
available. To enable, touch Guidance
Lines on the infotainment display
when a camera view is active.
Touching the button multiple times
will toggle through Standard
Guidelines, Hitch Guidance and no
guidelines. Standard guidelines are
available in Front/Rear Standard
Views, Front/Rear Top-Down Views
and Surround View.
Hitch Guidance displays a single
centered guideline on the
infotainment display to assist with
aligning the vehicle’s hitch ball with a
trailer coupler. Touch the Hitch
Guidance icon, then align the trailer
guidance line over the trailer coupler.
Continuously steer the vehicle to keep
the guideline centered on the coupler
when backing. Park Assist overlays will
not display when the trailer guidance
line is active. Hitch Guidance is
available in Rear Standard View.{Warning
Use Hitch Guidance only to help back the
vehicle to a trailer hitch or, when
traveling above 12 km/h (8 mph), to
briefly check the status of your trailer. Do
not use for any other purpose, such as
making lane change decisions. Before
making a lane change, always check the
mirrors and glance over your shoulder.
Improper use could result in serious
injury to you or others.
7. Interior Trailer View
Provides a view of the interior of the
trailer. The feature is available when a
trailer is connected. The feature
requires user installation of an
accessory trailer camera on the
interior of the trailer per the accessory
trailer camera installation instructions
(see your dealer for accessory trailer
camera(s) and information). To select,
touch Interior Trailer View on the
infotainment display when a camera
view is active. To access this view
when in a forward gear above
12 km/h (8 mph), touch CAMERA on
the infotainment display and touchthe Interior Trailer View icon. The view
will close after 8 seconds and can be
closed early by touching X.
8. Hitch View
Assists with connecting to a trailer by
providing a zoomed-in view of the
hitch to help align the vehicle’s hitch
ball with the trailer coupler, or to
monitor the trailer connection. To
select, touch Hitch View on the
infotainment display when a camera
view is active. To access this view
when in a forward gear above
12 km/h (8 mph), touch CAMERA on
the infotainment display and touch
the Cargo Bed View icon. The view
will close after 8 seconds and can be
closed early by touching X. Shifting
into P (Park) while in this view will
automatically engage the Electric
Parking Brake (EPB).
9. Bed View
Provides a view of the truck bed and
the area behind the vehicle to assist
in cargo or hitch monitoring or
hitching to a fifth wheel or gooseneck
trailer. To select, touch Bed View on
the infotainment display when a
camera view is active. To access this
view when in a forward gear above

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
276 Driving and Operating
Without Head-Up Display
When your vehicle approaches another
detected vehicle too rapidly, the red FCA
display will flash on the windshield. Also,
eight rapid high-pitched beeps will sound
from the front, or both sides of the Safety
Alert Seat will pulse five times. When this
Collision Alert occurs, the brake system may
prepare for driver braking to occur more
rapidly which can cause a brief, mild
deceleration. Continue to apply the brake
pedal as needed. Cruise control may be
disengaged when the Collision Alert occurs.
Tailgating Alert
The vehicle ahead indicator will display
amber when you are following a vehicle
ahead much too closely.
Selecting the Alert Timing
The Collision Alert control is on the steering
wheel. Press
[to set the FCA timing to
Far, Medium, or Near. The first button press
shows the current setting on the DIC.
Additional button presses will change this
setting. The chosen setting will remain until
it is changed and will affect the timing of
both the Collision Alert and the Tailgating
Alert features. The timing of both alerts will
vary based on vehicle speed. The faster the
vehicle speed, the farther away the alert will
occur. Consider traffic and weather
conditions when selecting the alert timing.
The range of selectable alert timings may
not be appropriate for all drivers and driving
conditions.
If your vehicle is equipped with Adaptive
Cruise Control (ACC), changing the FCA
timing setting automatically changes the
following gap setting (Far, Medium,
or Near).
Following Distance Indicator
The following distance to a moving vehicle
ahead in your path is indicated in following
time in seconds on the Driver Information
Center (DIC). The minimum following time is
0.5 seconds away. If there is no vehicle
detected ahead, or the vehicle ahead is out
of sensor range, dashes will be displayed.
Unnecessary Alerts
FCA may provide unnecessary alerts for
turning vehicles, vehicles in other lanes,
objects that are not vehicles, or shadows.
These alerts are normal operation and the
vehicle does not need service.
Cleaning the System
If the FCA system does not seem to operate
properly, this may correct the issue:
.Clean the outside of the windshield in
front of the rearview mirror.
.Clean the entire front of the vehicle.
.Clean the headlamps.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Driving and Operating 281
When the vehicle is started, both outside
mirror LCA displays will briefly come on to
indicate the system is operating. When the
vehicle is in a forward gear, the left or right
side mirror display will light up if a moving
vehicle is detected in the next lane over in
that blind zone or rapidly approaching that
zone. If the turn signal is activated in the
same direction as a detected vehicle, this
display will flash as an extra warning not to
change lanes.
LCA can be disabled through vehicle
personalization. When you disable LCA, SBZA
is also disabled. SeeVehicle Personalization
0 131. If LCA is disabled by the driver, the
LCA mirror displays will not light up.
When the System Does Not Seem to
Work Properly
The LCA system requires some driving for
the system to calibrate to maximum
performance. This calibration may occur
more quickly if the vehicle is driving on a
straight highway road with traffic and
roadside objects (e.g., guardrails, barriers).
LCA displays may not come on when
passing a vehicle quickly, for a stopped
vehicle, or when towing a trailer. The LCA
detection zones that extend back from the side of the vehicle do not move further back
when a trailer is towed. Use caution while
changing lanes when towing a trailer. LCA
may alert to objects attached to the vehicle,
such as a trailer, bicycle, or object extending
out to either side of the vehicle. Attached
objects may also interfere with the
detection of vehicles. This is normal system
operation; the vehicle does not need service.
LCA may not always alert the driver to
vehicles in the next lane over, especially in
wet conditions or when driving on sharp
curves. The system does not need to be
serviced. The system may light up due to
guardrails, signs, trees, shrubs, and other
non-moving objects. This is normal system
operation; the vehicle does not need service.
LCA may not operate when the LCA sensors
in the left or right corners of the rear
bumper are covered with mud, dirt, snow,
ice, or slush, or in heavy rainstorms. For
cleaning instructions, see "Washing the
Vehicle" under
Exterior Care0398. If the
DIC still displays the system unavailable
message after cleaning both sides of the
vehicle toward the rear corners of the
vehicle, see your dealer. If the LCA displays do not light up when
moving vehicles are in the side blind zone or
are rapidly approaching this zone and the
system is clean, the system may need
service. Take the vehicle to your dealer.
Radio Frequency Information
See
Radio Frequency Statement 0436.
Lane Keep Assist (LKA)
If equipped, LKA may help avoid crashes due
to unintentional lane departures. This
system uses a camera to detect lane
markings between 60 km/h (37 mph) and
180 km/h (112 mph). It may assist by gently
turning the steering wheel if the vehicle
approaches a detected lane marking. It may
also provide a Lane Departure Warning
(LDW) alert if the vehicle crosses a detected
lane marking. LKA can be overridden by
turning the steering wheel. This system is
not intended to keep the vehicle centered in
the lane. LKA will not assist and alert if the
turn signal is active in the direction of lane
departure, or if it detects that you are
accelerating, braking or actively steering.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Driving and Operating 305
To adjust Trailer Gain for each towing
condition:1. Drive the vehicle with the trailer attached on a level road surface
representative of the towing condition
and free of traffic at about 32–40 km/h
(20–25 mph) and fully apply the Manual
Trailer Brake Apply Lever.
Adjusting Trailer Gain at speeds lower
than 32–40 km/h (20–25 mph) may
result in an incorrect gain setting.
2. Adjust the Trailer Gain, using the Trailer Gain (+) or (−) adjustment buttons, to
just below the point of trailer wheel
lock-up, indicated by trailer wheel squeal
or tire smoke when a trailer wheel locks.
Trailer wheel lock-up may not occur if
towing a heavily loaded trailer. Adjust
the Trailer Gain to the highest allowable
setting for the towing condition.
3. Readjust Trailer Gain anytime vehicle loading, trailer loading, or road surface
conditions change or if trailer wheel
lock-up is noticed at any time while
towing.Other ITBC-Related DIC Messages
TRAILER CONNECTED: This message will
briefly display when a trailer with electric
brakes is first connected to the vehicle. This
message will automatically turn off in about
10 seconds. This message can be
acknowledged before it automatically
turns off.
CHECK TRAILER WIRING: This message will
display if:
.The ITBC system first determines
connection to a trailer with electric brakes
and then the trailer harness becomes
disconnected from the vehicle.
If the disconnect occurs while the vehicle
is stationary, this message will
automatically turn off in about
30 seconds. This message will also turn
off if it is acknowledged or if the trailer
harness is reconnected.
If the disconnect occurs while the vehicle
is moving, this message will continue
until the ignition is turned off. This
message will also turn off if it is
acknowledged or if the trailer harness is
reconnected.
.There is an electrical fault in the wiring to
the trailer brakes. This message will
continue as long as there is an electrical
fault in the trailer wiring. This message
will also turn off if it is acknowledged.
To determine whether the electrical fault is
on the vehicle side or trailer side of the
trailer wiring harness connection: 1. Disconnect the trailer wiring harness from the vehicle.
2. Turn the ignition off.
3. Wait 10 seconds, then turn the ignition back to RUN.
4. If the CHECK TRAILER WIRING message reappears, the electrical fault is on the
vehicle side.
If the CHECK TRAILER WIRING message only
reappears when connecting the trailer wiring
harness to the vehicle, the electrical fault is
on the trailer side.
SERVICE TRAILER BRAKE SYSTEM: This
message will display when there is a
problem with the ITBC system. If this
message continues over multiple ignition
cycles, have the vehicle serviced.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
332 Vehicle Care
Engine Oil Additives/Engine Oil Flushes
Do not add anything to the oil. The
recommended oils meeting the dexos1
specification are all that is needed for good
performance and engine protection.
Engine oil system flushes are not
recommended and could cause engine
damage not covered by the vehicle
warranty.
What to Do with Used Oil
Used engine oil contains certain elements
that can be unhealthy for your skin and
could even cause cancer. Do not let used oil
stay on your skin for very long. Clean your
skin and nails with soap and water, or a
good hand cleaner. Wash or properly
dispose of clothing or rags containing used
engine oil. See the manufacturer's warnings
about the use and disposal of oil products.
Used oil can be a threat to the environment.
If you change your own oil, be sure to drain
all the oil from the filter before disposal.
Never dispose of oil by putting it in the
trash or pouring it on the ground, into
sewers, or into streams or bodies of water.
Recycle it by taking it to a place that
collects used oil.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system that
indicates when to change the engine oil and
filter. This is based on a combination of
factors which include engine revolutions,
engine temperature, and miles driven. Based
on driving conditions, the mileage at which
an oil change is indicated can vary
considerably. For the oil life system to work
properly, the system must be reset every
time the oil is changed.
On some vehicles, when the system has
calculated that oil life has been diminished,
a CHANGE ENGINE OIL SOON message comes
on to indicate that an oil change is
necessary. Change the oil as soon as
possible within the next 1 000 km (600 mi).
It is possible that, if driving under the best
conditions, the oil life system might indicate
that an oil change is not necessary for up to
a year. The engine oil and filter must be
changed at least once a year and, at this
time, the system must be reset. For vehicles
without the CHANGE ENGINE OIL SOON
message, an oil change is needed when the
REMAINING OIL LIFE percentage is near 0%.
Your dealer has trained service people whowill perform this work and reset the system.
It is also important to check the oil regularly
over the course of an oil drain interval and
keep it at the proper level.
If the system is ever reset accidentally, the
oil must be changed at 5 000 km (3,000 mi)
since the last oil change. Remember to reset
the oil life system whenever the oil is
changed.
How to Reset the Engine Oil Life System
Reset the system whenever the engine oil is
changed so that the system can calculate
the next engine oil change. Always reset the
engine oil life to 100% after every oil
change. It will not reset itself. To reset the
engine oil life system:
1. Display the oil life percentage on the DIC. See Driver Information Center (DIC)
(Base Level) 0124 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0125.
2. Press the thumbwheel on the steering wheel, or the trip odometer reset stem if
the vehicle does not have DIC controls,
for several seconds. When the
confirmation message displays, select
YES. The oil life will change to 100%.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Vehicle Care 333
The oil life system can also be reset as
follows:1. Display the oil life percentage on the DIC. See Driver Information Center (DIC)
(Base Level) 0124 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0125.
2. Fully press the accelerator pedal slowly three times within five seconds.
3. If the display changes to 100%, the system is reset.
If the vehicle has a CHANGE ENGINE OIL
SOON message and it comes back on when
the vehicle is started and/or the oil
life percentage is near 0%, the engine oil
life system has not been reset. Repeat the
procedure.
Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the
transmission fluid level. The only reason for
fluid loss is a transmission leak or
overheated transmission. This vehicle is not
equipped with a transmission fluid level
dipstick. There is a special procedure for
checking and changing the transmission fluid in these vehicles. Because this procedure is
difficult, this should be done at the dealer.
Contact the dealer for additional information
or the procedure can be found in the service
manual. See
Publication Ordering
Information 0435.
Caution
Use of the incorrect automatic
transmission fluid may damage the
vehicle, and the damage may not be
covered by the vehicle warranty. Always
use the correct automatic transmission
fluid. See Recommended Fluids and
Lubricants 0418.
Change the fluid and filter at the scheduled
maintenance intervals listed in Maintenance
Schedule 0409. Be sure to use the
transmission fluid listed in Recommended
Fluids and Lubricants 0418.
Engine Air Filter Life System
If equipped, this feature provides the engine
air filter’s remaining life and best timing for
a change. The timing to change an engine
air filter depends on driving and
environmental conditions.
When to Change the Engine Air Filter
When the Driver Information Center (DIC)
displays a message to replace the engine air
filter at the next oil change, follow this
timing.
When the DIC displays a message to replace
the engine air filter soon, replace the engine
air filter at the earliest convenience.
The system must be reset after the engine
air filter is changed.
If the DIC displays a message to check the
engine air filter system, see your dealer.
How to Reset the Engine Air Filter Life
System
To reset:
1. Place the vehicle in P (Park).
2. Display the Air Filter Life on the DIC. See Driver Information Center (DIC) (Base
Level) 0124 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0125.
3. Press
Ton the steering wheel, or press
the trip odometer reset stem if the
vehicle does not have DIC controls, to
move to the Reset/Disable display area.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
342 Vehicle Care
Brake Pedal Travel
See your dealer if the brake pedal does not
return to normal height, or if there is a
rapid increase in pedal travel. This could be
a sign that brake service may be required.
Replacing Brake System Parts
Always replace brake system parts with
new, approved replacement parts. If this is
not done, the brakes may not work
properly. The braking performance can
change in many ways if the wrong brake
parts are installed or if parts are improperly
installed.
Brake Pad Life System
When to Change Brake Pads
This vehicle has a system that estimates the
remaining life of the front and rear brake
pads. Brake pad life is displayed in the
Driver Information Center (DIC), along with
a percentage for each axle. The system must
be reset every time the brake pads are
changed.
When the system has determined that the
brake pads need to be replaced, a message
will display, which may include mileage
remaining.Brake pads should always be replaced as
complete axle sets.
How to Reset the Brake Pad Life System
The system will automatically detect when
significantly worn brake pads are replaced.
When the ignition is turned on after new
pads and wear sensors are installed, a
message will display. Follow the prompts to
reset the system.
The brake pad life system can also be
manually reset:
1. Display Brake Pad Life on the DIC. See Driver Information Center (DIC) (Base
Level) 0124 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0125.
2. Press the thumbwheel or the trip odometer reset stem if the vehicle does
not have DIC buttons. Select front or rear
pads as appropriate.
3. Select YES on the confirmation message, or press the trip odometer reset stem on
a base level DIC. Repeat for pads on the
other axle if they were also replaced.
How to Disable the Brake Pad Life
System
The brake pad life system can be turned off.
This may be necessary if aftermarket brake
pads without wear sensors are installed.
When the system is turned off, the front
and rear brake pad life percentages will not
display. However, the built-in wear
indicators that make a high-pitched warning
sound when the brake pads are worn can
still determine when the pads should be
replaced. See Brakes0341.
To turn off the brake pad life system: 1. Display Brake Pad Life on the DIC. See Driver Information Center (DIC) (Base
Level) 0124 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0125.
2. Select DISABLE.
To turn the brake pad life system back on,
follow the above steps but select ENABLE in
Step 2.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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346 Vehicle Care
3. Turn the ignition on.
For vehicles not equipped with the Stop/
Start system: 1. Install the negative battery cable clamp to the negative battery post.
2. Tighten the negative battery cable nut.
3. Turn the ignition on.
Four-Wheel Drive
Transfer Case
When to Check Lubricant
Refer to Maintenance Schedule 0409 to
determine when to check the lubricant.
1. Fill Plug
2. Drain Plug
To get an accurate reading, the vehicle
should be on a level surface.
If the level is below the bottom of the fill
plug (1) hole, located on the transfer case,
some lubricant will need to be added. Add
enough lubricant to raise the level to the
bottom of the fill plug (1) hole. Use care not
to overtighten the plug.
When to Change Lubricant
Refer to Maintenance Schedule 0409 to
determine how often to change the
lubricant.
What to Use
Refer to Recommended Fluids and Lubricants
0 418 to determine what kind of lubricant
to use.
Front Axle
When to Check Lubricant
It is not necessary to regularly check the
front axle fluid unless a leak is suspected or
an unusual noise is heard. A fluid loss could
indicate a problem. Have it inspected and
repaired. This service can be complex. See
your dealer. Do not directly power wash the transfer
case and/or front/rear axle output seals.
High pressure water can overcome the seals
and contaminate the fluid. Contaminated
fluid will decrease the life of the transfer
case and/or drive axles and should be
replaced.
Rear Axle
When to Check Lubricant
It is not necessary to regularly check the
rear axle fluid unless a leak is suspected or
an unusual noise is heard. A fluid loss could
indicate a problem. Have it inspected and
repaired. This service can be complex. See
your dealer.
Do not directly power wash the transfer
case and/or front/rear axle output seals.
High pressure water can overcome the seals
and contaminate the fluid. Contaminated
fluid will decrease the life of the transfer
case and/or drive axles and should be
replaced.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Vehicle Care 375
Lightly coat the inner diameter of the
wheel hub opening with wheel bearing
grease after a wheel change or tire
rotation to prevent corrosion or rust
build-up.
{Warning
Do not apply grease to the wheel
mounting surface, wheel conical
seats, or the wheel nuts or bolts.
Grease applied to these areas could
cause a wheel to become loose or
come off, resulting in a crash.
When It Is Time for New Tires
Factors, such as maintenance, temperatures,
driving speeds, vehicle loading, and road
conditions affect the wear rate of the tires.
Treadwear indicators are one way to tell
when it is time for new tires. Treadwear
indicators appear when the tires have only
1.6 mm (1/16 in) or less of tread remaining.
See Tire Inspection 0373 and
Tire Rotation 0374 for additional
information.
The rubber in tires ages over time. This also
applies to the spare tire, if the vehicle has
one, even if it is never used. Multiple factors
including temperatures, loading conditions,
and inflation pressure maintenance affect
how fast aging takes place. GM recommends
that tires, including the spare if equipped,
be replaced after six years, regardless of
tread wear. To identify the age of a tire, use
the tire manufacture date, which is the last four digits of the DOT Tire Identification
Number (TIN) molded into one side of the
tire sidewall. The last four digits of the TIN
indicate the tire manufactured date. The
first two digits represent the week and the
last two digits, the year. For example, the
third week of the year 2020 would have a
4-digit DOT date of 0320. Week 01 is the
first full week (Sunday through Saturday) of
each year.
Vehicle Storage
Tires age when stored normally mounted on
a parked vehicle. Park a vehicle that will be
stored for at least a month in a cool, dry,
clean area away from direct sunlight to slow
aging. This area should be free of grease,
gasoline, or other substances that can
deteriorate rubber.
Parking for an extended period can cause
flat spots on the tires that may result in
vibrations while driving. When storing a
vehicle for at least a month, remove the
tires or raise the vehicle to reduce the
weight from the tires.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
380 Vehicle Care
If a Tire Goes Flat
It is unusual for a tire to blowout while
driving, especially if the tires are maintained
properly. If air goes out of a tire, it is much
more likely to leak out slowly. But if there
ever is a blowout, here are a few tips about
what to expect and what to do:
If a front tire fails, the flat tire creates a
drag that pulls the vehicle toward that side.
Take your foot off the accelerator pedal and
grip the steering wheel firmly. Steer to
maintain lane position, and then gently
brake to a stop, well off the road,
if possible.
A rear blowout, particularly on a curve, acts
much like a skid and may require the same
correction as used in a skid. Stop pressing
the accelerator pedal and steer to straighten
the vehicle. It may be very bumpy and
noisy. Gently brake to a stop, well off the
road, if possible.{Warning
Driving on a flat tire will cause
permanent damage to the tire.
Re-inflating a tire after it has been driven
on while severely underinflated or flat
may cause a blowout and a serious crash.
Never attempt to re-inflate a tire that has
been driven on while severely
underinflated or flat. Have your dealer or
an authorized tire service center repair or
replace the flat tire as soon as possible.
{Warning
Lifting a vehicle and getting under it to
do maintenance or repairs is dangerous
without the appropriate safety equipment
and training. If a jack is provided with
the vehicle, it is designed only for
changing a flat tire. If it is used for
anything else, you or others could be
badly injured or killed if the vehicle slips
off the jack. If a jack is provided with the
vehicle, only use it for changing a
flat tire.If a tire goes flat, avoid further tire and
wheel damage by driving slowly to a level
place, well off the road, if possible. Turn on
the hazard warning flashers. See
Hazard
Warning Flashers 0142.
{Warning
Changing a tire can be dangerous. The
vehicle can slip off the jack and roll over
or fall causing injury or death. Find a
level place to change the tire. To help
prevent the vehicle from moving:
1. Set the parking brake firmly.
2. Shift the vehicle to P (Park).
3. For vehicles with four-wheel drive with an N (Neutral) transfer case
position, be sure the transfer case is
in a drive gear —not in N (Neutral).
4. Turn off the engine and do not restart while the vehicle is raised.
5. Do not allow passengers to remain in the vehicle.
6. Place wheel blocks, if equipped, on both sides of the tire at the opposite
corner of the tire being changed.