Until the day comes when we are all piloting flying cars (and trust me, the day will come), our cars are stuck with these rubber things called tires. They roll nice and all, but they have a rather nasty problem of sometimes losing air. And without air, they become deflated and virtually useless.
Changing a flat tire is not a very pleasant experience. It seems like your car purposely tries to get a flat tire at the least opportune moments. Like when you are rushing home from work to catch your favorite episode of "Happy Days," for instance. You know, the one where Fonzie rides the killer bull while on vacation in Colorado.
Now, there are some of you who might be lucky and own a car with run-flat tires or a low tire-pressure warning system. If that is the case, you might be able to avoid the icky process. But even if you are a hapless soul, changing a tire doesn't have to be all bad. With knowledge comes power. If you are unsure how to change a tire properly, and you want to know, read on.
OK, so you are driving along and all of the sudden you hear a loud bang and the telltale thumping noise of a dead tire. You carefully pull off to the shoulder of the road. Checking to make sure no other motorists are going to run you over, you exit your vehicle and inspect the car. Sure enough, your car's left front tire is completely flat. You are not going to be able to keep driving, so you are going to have to remove it and install your car's spare tire in its place.
Jack up the Car
The first step is to find your car's spare tire, jack and tire iron. The spare tire is almost always located underneath the floor mat in the trunk. Unless, of course, your car doesn't have a trunk. If you own an SUV, minivan or pickup, the spare tire is often mounted on the back of the tailgate or underneath the vehicle itself.
Once you have found the spare tire, remove it from the car. If you have an air pressure gauge handy, you will want to check the spare tire's pressure. If this tire is flat, too, you're in a bit of trouble. But let's just assume you have been keeping tabs on the spare tire's health, and its air pressure is perfect.
The next step will involve removing the flat tire. Make sure that the car is in gear (or in "park" if the car is an automatic) and the emergency brake is set. The car should be parked on a flat piece of pavement. Do not attempt to change a flat if the car is on a slope or if it is sitting on dirt. It's also a good idea to block the tire opposite of the flat tire. Therefore, if the left front tire is flat, it would be a good idea to place a brick or other large, heavy object behind the right rear tire. Blocking the tire makes the car less likely to move when you are raising it.
Use the tire iron (the L-shaped bar that fits over the wheel lugs) to loosen each wheel lug. The wheel lugs are almost certainly very tight. You'll have to use brute force. Just think about how Mr. T from the "A-Team" would do it and try to be like him. Say to yourself, "Hannibal, I piddy da fool who can't break loose wheel lugs." You'll have those babies loose in no time. You loosen them by turning them counterclockwise, by the way.
Now, at this point, you don't want to actually remove the lugs. You just want them loose. Once you have accomplished this, move the jack underneath the car. If you don't know where the proper jacking points are, look them up in the owner's manual.
Maneuver the jack underneath the jack point and start to raise the jack. Most car jacks these days are a screw-type scissor jack, which means you simply turn the knob at the end of the jack using the provided metal hand crank. Raise the jack until it contacts the car's frame and continue expanding the jack.
Remove the Flat and Install the Spare
Raise the car with the jack until the flat tire is completely raised off the ground. Once this is done, remove the wheel lugs completely. Depending on how tight the lugs are you might be able to remove them by hand. Set the lugs aside in a secure location where they can't roll away.
Position the spare tire over the wheel studs. This is the most physically challenging part of the whole process. You'll have to hold up the tire and try to line up the holes in the wheel with the protruding wheel studs located on the brake hub. One trick that might help is to balance the tire on your foot while you move it into position.
After you have the spare tire hanging on the wheel studs, screw each of the wheel lugs back on. You'll want to start them by hand. Make sure you do not cross-thread them. The lugs should screw on easily. Once each of them is snug and you can't tighten them any further by hand, use the tire iron to finish the job. At this point, you don't need to get the lugs super tight. You just want them snug for now. Make sure that the wheel is fitting flush against the brake hub.
Once the spare tire is on, carefully lower the jack. Pull the jack away from the vehicle. The final step is to tighten down the lugs completely. The reason you tighten the lugs now is that the tire is on the ground and it won't rotate around like it would if it was still hanging in the air.
Wheel lugs have a specific torque rating that they are supposed to be tightened down to, but there is pretty much no way you can figure that out using a simple tire iron. The general rule here is to tighten down the lugs as much as possible.
That's it. Put the flat tire in the space where the spare tire was and put the jack and tire iron back in the car. Most compact spare tires are smaller than regular tires, so it is possible that the flat tire won't fit in the spare tire well. Also, compact spares have a limited top speed. The tire's top speed will be written on its sidewall. If your vehicle has a full-size spare, you won't encounter these problems. With the spare installed, you should be able to reach your house or the nearest service station.
Source: Edmunds
