How to Change a Flat Tire on an Automobile
Flat tire blow outs are typically not that common while driving, especially if you maintain your tires
properly. The majority of the time, a flat tire will be caused by air slowly leaking out of the tire. If you
ever experience a flat tire, the following instructions will help you with the equipment and processes
involved in changing a flat tire.
Caution: Injury can occur when changing a flat tire if proper pre-cautionary measures
are not taken to stabilize the car. The vehicle could slip off of the jack and roll over you
or other individuals. It is best to find a level place to change your tire. The following precautionary measures will help prevent someone from being badly injured:
1. Set the parking brake firmly.
2. Place the automatic transmission shift lever in PARK (P) or place the gear shift lever
of a manual transmission in FIRST (1) or REVERSE (R).
3. Turn off the engine.
4. Place wheel blocks at the front and rear of the tire farthest away from the flat tire.
That would be the tire on the other side of the vehicle at the opposite end as shown in
Figure 1 below.
Figure 1: Placement of wheel blocks
Below, in Figure 2, you will find an image containing all of the equipment needed to change a flat tire on
an automobile.
Wheel Blocks
Jack
Wheel Wrench
Figure 2: Equipment Needed to Change a Flat Tire
Notice: Never remove or mount a tire to
its stowage position underneath a
vehicle while it is being supported by a
jack. The vehicle could slip off the jack
and cause serious injury.
Removing the Spare Tire and Tools
The equipment needed to change a flat tire (jack and wheel wrench) is usually located along the driver’s
side rear wall, the passenger-side rear wall, or underneath the hood of your car mounted near either wheel
well. Your vehicle’s spare tire will be located either underneath the rear end of the car, inside the rear of
the car underneath the trunk floor, inside the rear of the car mounted on either side wall, or outside of the
car mounted on a carrier arm of a tailgate.
Once you have located and removed the equipment needed to change the flat you will need to remove the
spare tire.
To remove an underbody-mounted spare, do the following:
1. Insert the chisel end of the wheel wrench at an angle into the hole in the rear bumper.
Figure 3: Underbody-mounted spare tire access
Photo Courtesy of General Motors
2. Be sure that the chisel end of the wheel wrench is connected to the hoist shaft by examining
whether or not you experience resistance from turning the wrench either direction.
3. Turn the wheel wrench counterclockwise to lower the spare tire. Continue lowering until the
spare can be pulled out from underneath the vehicle.
4. When the tire has been completely lowered, tilt the retainer at the end of the cable and pull it
through the wheel opening. Proceed to pull the tire out from underneath the vehicle.
To remove an inside-mounted spare tire, do the following:
1. Reach into the spare tire’s cover, unscrew (counterclockwise direction) and remove the wing nut
at the center of the wheel.
Figure 4: Inside-mounted spare tire access and removal
2. Remove the cover and unhook the tire from its mounting bracket.
To remove a rear-mounted spare tire on a carrier arm, do the following:
1. First make sure the carrier arm is fully latched to the tailgate of the vehicle.
2. Remove the spare tire cover.
3. Use the wheel wrench to loosen (counterclockwise direction) and remove each of the wheel nuts
(otherwise known as lug nuts) holding the spare tire in place – typically there are at least three lug
nuts to remove.
Figure 5: Removal of a Rear-mounted Spare Tire
4. Remove the spare tire.
Removing the Flat tire and Installing the Spare Tire
If your vehicle has individual wheel nut caps that cover each nut, you will need to first remove them using
the wheel wrench to access the actual lug nuts.
Figure 6: Individual Wheel Nut Caps - Removal
Caution: Do not place any portion of your body underneath the vehicle while it
is jacked up. The vehicle could slip and fall off the jack at any moment and cause
serious injury. Never place yourself under a vehicle when it is supported by a
jack. It is important that you properly fit the jack lift head into a good location
prior to raising the vehicle to help prevent such incidents.
Perform the following tasks to remove the flat tire:
1. Utilize the wheel wrench to loosen all of the lug nuts prior to raising the vehicle. DO NOT
remove the lug nuts. The wheel could “pop” off of the mounting system due to the pressure
created by the weight of the vehicle.
Figure 7: Loosening the Wheel Lug Nuts Prior to Raising the Vehicle
2. Place the jack underneath a solid portion of the vehicle’s frame closest to the flat tire.
Frame
Figure 8: Placement of the Jack under a Solid Portion of the Frame
3. Turn the jack handle clockwise to raise the lifting head of the jack. Raise the vehicle high enough
off of the ground such that the flat tire can be removed and the spare tire can be mounted (usually
about an inch to three inches will suffice).
Figure 9: Raising the Vehicle using the Jack
4. Remove all of the lug nuts and the flat tire.
5. Remove any dirt, rust, and debris from the wheel bolts, and mounting surfaces prior to mounting
the spare tire.
Figure 10: Inspecting and Removing Excessive Dirt, Rust, and Debris
6. Mount the spare tire by aligning the holes with the wheel bolts.
Tip: It is easiest to set the spare tire on the mounting assembly first at an angle to help reduce the
weight a user must support. Allow the mounting system to serve as a prop while properly aligning
the holes in the wheel with the wheel bolts.
Figure 11: Aligning the Spare Tire
7. Mount the lug nuts by hand first to ensure that you do not cross-thread (screwing together two
threaded pieces without properly aligning the threads) them with the wheel bolts. Be sure to place
the cone-shaped ends of the lug nuts towards the wheel. Tighten the lug nuts by hand until the
wheel is held against the hub. If a lug nut is unable to be turned by hand, use the wheel wrench,
but be sure to visit your dealer as soon as possible to have your lug nuts and wheel bolts properly
examined. It is possible that the wheel bolt is excessively rusty or was ruined by the occurrence of
the flat tire.
Figure 12: Mounting the Spare Tire
8. Check to make sure there is nothing under the vehicle and lower the jack by turning the jack
handle counterclockwise. Lower the jack completely.
9. Use the wheel wrench to tighten the lug nuts firmly in a crisscross pattern as shown in Figure 13.
Be sure to double check the tightness of each lug nut.
Caution: Incorrect
or improperly tightened
wheel lug nuts can cause the
wheel to become loose and
even come off. This could
cause a serious accident.
Figure 13: Crisscross Pattern for Tightening Wheel Lug Nuts
10. Stop somewhere as soon as possible to have the wheel lug nuts tightened with a torque wrench to
a specific torque rating (i.e. 100 lb-ft). Below, in Figure 14, is a typical torque wrench.
Figure 14: Torque Wrench
To finish up the process of changing a flat tire store the equipment and the flat tire by reversing the steps
listed for their removal.
Once you have properly stored all the equipment, you are ready to get back on the road. Use caution as
you enter the highway and be aware of the spare tire as it may cause your vehicle to handle differently
than normal. If you notice a significant vibration or if you notice a vibration developing and worsening,
immediately pull over and examine the spare tire and the tightness of the lug nuts. It could be that you
missed tightening one of the wheel lug nuts. Small amounts of vibration are going to be typical while
using a spare tire due to its difference in size. Even if a spare tire is a full size spare (meaning it is the
same size as the typical tire on your vehicle), it may have a different tread pattern and therefore cause
noise and vibration – do not be alarmed by this.