Semi Truck Tire Blowout: What to Do in the First 60 Seconds
A steer tire blowout at 65 mph is survivable if you do the counterintuitive thing. The correct first 60 seconds, and how to get safe once you are stopped.
A steer tire lets go like a shotgun going off under your feet, and the truck immediately tries to leave the road on the side that blew. What you do in the next three seconds decides whether this is a bad afternoon or a rollover.
The instincts you were born with are all wrong here. Every one of them. Read this before it happens, because there is no time to reason it out when it does.
The first three seconds: do not brake, do not lift
Your foot wants to jump off the throttle and stand on the brake. Both will hurt you. Lifting abruptly throws weight forward onto a steer axle that just lost a tire. Braking hard makes the truck pull harder toward the failed side and can jackknife the trailer behind you.
- Both hands on the wheel, hold on hard. A blown steer will try to rip it out of one hand.
- Hold the throttle. On a steer blowout, a brief squeeze of throttle pulls the truck straight against the drag of the flat. Counterintuitive, correct, and it works.
- Steer straight ahead with small inputs. Do not swerve for the shoulder and do not overcorrect the pull.
- Once it is tracking straight, ease off the throttle gradually and let the truck slow itself.
- Brake gently and progressively only after you are straight and slow.
- Signal, ease onto the shoulder, get as far right as you can, look for level ground, hazards on.
Say it out loud a few times before you ever need it. Hold the wheel, hold the throttle, steer straight, then slow down.
Steer, drive and trailer fail differently
A steer blowout is the violent one, because you are steering with it. That is the sequence above.
A drive or trailer tire on a dual usually announces itself as a bang and then a rhythmic slapping as the carcass comes apart and beats the fender, the mudflap, the air lines and anything else in reach. The truck stays controllable because the mate is holding the load. Less dramatic, still a stop-now situation.
Do not limp a blown dual to the next exit. The mate is now carrying double the load it was built for, it heats up fast, and a shredded tire next to a hot wheel end and a fuel tank is how a truck ends up on the news. A blown trailer tire can also tear out an air line and drop the trailer brakes on you, so if the truck starts dragging afterward, that is why.
Getting stopped is not the same as getting safe
- Hazards on the second you know you have a problem, before you are even slowed down.
- Get off the road as far as the shoulder allows, on level ground if you have any choice.
- Get out on the passenger side. Never step into a live lane.
- Do not stand between your truck and traffic, and do not sit in the cab on a narrow shoulder. Get behind the guardrail or up the bank, well away from the truck.
- If the tire is smoking or you smell rubber burning, get clear and stay clear. Do not go look.
Federal rules give you ten minutes to get warning devices out. On a two-lane road, one within 10 feet of the rear on the traffic side, one about 100 feet behind, one about 100 feet ahead. On a divided or one-way highway, all three go behind you at roughly 10, 100 and 200 feet. If there is a hill or a curve behind you, walk the far one back further, 100 to 500 feet, so traffic sees it before it sees you.
The point is not compliance. A car at 70 mph covers a hundred feet a second and needs far more warning than four-ways can give him.
Do not attempt a steer tire change on the shoulder of an interstate, and never get under a truck supported by a jack. A jack on soft shoulder dirt walks, and a loaded rig coming down on you is not survivable. If the tire has to come off, that is a call, not a project.
Why it blew, and how to stop the next one
Blowouts are rarely bad luck. Ranked by how often they are the actual cause:
- Underinflation, by a wide margin. A soft tire flexes, the sidewall builds heat, and heat destroys the tire from the inside long before it lets go. Retreads get blamed for a lot of failures that were really a tire running 25 percent low for a month.
- Thumping tires with a bar. It finds a flat. It does not find a tire that is 20 psi low, and 20 psi low is what kills tires. Use a gauge, check them cold, check all of them including the inside duals.
- Mismatched duals. A quarter inch of diameter difference between mates makes the taller tire carry more than its share, every mile.
- Overloading, and scrubbing sidewalls on curbs.
- Road hazard, which is the only one on this list you cannot prevent.
- A dragging brake or a failing wheel bearing cooking the tire from the rim outward. If a tire blows and the hub is hot, the tire was the symptom, not the disease.
Tread depth matters too. The floor is 4/32 on the steer axle and 2/32 everywhere else, and a bald tire is also a tire whose belts have been running hot for a long time.
When you are down on the shoulder, the fastest way back is somebody who brings the tire to you. Duckett Roadside Repair does mobile tire service, new and used, mount and balance, out on the road across Milton, Pace, Pensacola, Navarre, Crestview and the I-10 corridor. Dispatch answers at (850) 495-0366, 24 hours a day, 7 days a week. Give them the tire size and the position, get behind the guardrail, and wait for the truck.