If there is no way for you to avoid a pothole, don’t brake suddenly. This will avert damage and impacts to your vehicle.
When a wheel hits a pothole, it drops into the hole and has to roll out of it. The damage is almost never due to the wheel entering the hole; it’s the impact on exiting that causes it. The amount of damage depends on the diameter of the tire, the depth and length of the pothole, and the speed of the vehicle.
When a tire rolls over irregularities in the road, most of the force exerted on the suspension is directed upward, because the bottom of the tire is what contacts the road.
The higher up the tire the impact, the more the force of the impact will push the wheel both backward and upward. The smaller the wheel diameter, the more severe the impact will be, especially if the depth of the hole is the same as the diameter of the wheel.
Longer potholes cause more damage because their length means that at practically any speed, the tire is likely to hit bottom before exiting.
Similarly, low speed can result in damage to the vehicle’s frame or platform because, here again, the tire has time to hit the bottom of the hole.
When a tire hits the inside of a pothole, it is pushed both backward and upward, transmitting the force of impact to the wheel, the suspension and the steering mechanism.
The most likely types of damage are loss of a hubcap, a damaged tire, a bent or broken wheel, wheels knocked out of alignment, damaged suspension components, bent steering parts, and damaged shock absorbers.
- Hubcaps are often attached to wheels only by pressure clamps, so they can easily fly off; replacements can cost $20 to $150 each.
- The tire is the first thing to absorb the impact, and this can break its interior structure and/or tear the sidewall. An overinflated tire runs a greater risk of structural damage, whereas an underinflated tire might rupture when squeezed between the pothole and the wheel.
- Low-profile tires — more and more late-model cars are equipped with them — can sustain severe damage from this kind of impact. If you have any doubts after a collision with a pothole, it would be wise to have your tires examined by a specialist: if a tire’s belt is broken, this could pose a serious safety hazard.
- A replacement tire can cost anywhere from $70 to more than $400.
- If the tire doesn’t absorb the entire shock — if it’s underinflated, for example — the wheel will suffer the consequences. It may bend, crack, or break as a result of the impact.
- Repair options for a wheel are quite limited, so more often than not it will have to be replaced. Alloy wheels are both more fragile and more expensive. While a new steel wheel may cost $40 to $200, some alloy wheels sell for more than $500.
- A wheel falling into a pothole is subject to both vertical and horizontal force. These forces are transmitted to the suspension, which is meant to move up and down. If there is enough horizontal force, suspension parts (like the suspension arm) as well as steering parts (like the steering linkage, or tie rod) can be damaged and the wheels knocked out of alignment. A replacement linkage can cost between $75 and $250, depending on the make of car, while a new suspension arm can lighten your wallet by $150 to more than $350.
- If the wheels are not realigned, tires can wear quickly and driving the vehicle may become noticeably uncomfortable. A wheel alignment can cost $50 to $150 or more, depending on how sophisticated the steering system is and how much damage has been done.
- Shock absorbers rarely break under impact with potholes. These components usually wear out due to extensive driving on bad roads.
- There are ways to tell if a shock absorber is reaching the end of its useful life. Oil leaking from a shock absorber is a bad sign, but it doesn’t necessarily mean it needs replacing. The reverse is also true, however: a shock absorber may show no signs of leaking, but that doesn’t mean it’s still in top shape.
- The best way to check is to push down hard two or three times on a corner of the vehicle, then let go when the car is at its lowest point. If the car bounces twice or more, it’s time to change that shock absorber. Repeat the test on all four corners of the vehicle.
- You may have no choice but to replace the shock absorbers at either end of the same axle. A shock absorber can cost from $50 to upwards of $500.
Although Quebec municipalities and the provincial Ministry of Transport were legally released from liability for pothole damage to vehicles in 1993, you may still be entitled to compensation. See our Tips & Tricks instalment Pothole damage: Claims and compensation.
You can also contact your insurer to see if it is more advantageous to submit an insurance claim, depending on the deductible specified in your policy.
If, after you have opened a claim file and assessed the costs, you choose not to submit a claim to your insurer after all, there will still be a record of this in your claims history in the central claims registry, the Fichier central des sinistres (it will be flagged “Fermé sans indemnisation”; i.e., “File closed without compensation”).
Don’t try to swerve around a pothole if there’s a chance that your avoidance manoeuvre will result in an accident.
If you weren’t able to avoid a pothole and you want to stop and inspect damage to your car, be sure to park in a safe place.
Never stop on a highway to attempt to recover a lost hubcap: you could be struck by a passing vehicle. If you do stop for this reason on slower, less busy road, make sure there is no danger to yourself or other road users.