Finch, Steeles and half the side streets in the city go through the same thing every March and April. Water gets into cracks in the asphalt, freezes overnight, expands, thaws in the afternoon and does it all again the next night. By the time the snow is gone, the road surface is breaking apart under traffic.
A hard pothole hit doesn't always do visible damage. Often the car feels a bit different afterward, and the cost shows up weeks later in a worn tire edge or a slow leak.
What a hard hit can damage
- Tires. A sharp edge can pinch the tire between the road and the rim and break the cords inside the sidewall. That shows up as a bulge or bubble on the sidewall, sometimes days later. A sidewall bubble can't be repaired. The tire needs replacing, because it can fail without warning.
- Rims. Alloy wheels can bend or crack at the lip. A bent rim often causes a slow leak where the tire seals against the wheel, or a vibration at highway speed. Some bends can be straightened by a wheel repair specialist. A cracked wheel generally needs replacing.
- Alignment. The impact can knock the toe and camber settings out, so the tires no longer point straight. The car pulls, the steering wheel sits off-centre and the tires start wearing unevenly.
- Steering parts. Tie rods and tie rod ends can bend. A bent tie rod can't just be adjusted back into spec; it has to be replaced, then the alignment set.
- Suspension. Ball joints, control arms, sway bar links, struts and strut mounts all take the hit. Damage here often shows up as a clunk over bumps.
- Balance weights. A hard hit can knock a wheel weight off, leaving a vibration that wasn't there before.
Signs to watch for afterward
After a hard hit, pull over when it's safe and look at the tire on that corner. Over the next few days, pay attention to:
- The steering wheel sitting off-centre when you're driving straight
- The car pulling or drifting to one side on a flat road
- A new vibration in the steering wheel or seat, often starting around 80 to 100 km/h
- A tire that keeps losing pressure, or a TPMS light that keeps coming back
- A bulge on the sidewall
- Clunking, knocking or rattling over bumps
- Steering that feels loose or wanders on the highway
Any one of these is worth a check. A sidewall bulge or a sudden strong pull should be looked at before you drive any distance on the highway.
Why alignment matters after a hit
Alignment is the set of angles that control how the tires sit on the road. Toe is whether the front edges of the tires point slightly in or out. Camber is how much they tilt in or out at the top. Caster is the angle of the steering axis, which affects stability and how the steering wheel returns to centre.
A car can be out of alignment and still feel mostly normal. The cost shows up in the tires: an edge worn down months early, or a feathered tread that roars on the highway. On a new set, a bad alignment can take thousands of kilometres off their life in a single season.
An alignment check puts the car on a machine that measures each angle and compares it to the manufacturer's specifications. If a part is bent, the readings usually give it away, because that angle won't adjust back into range.
Making the next one hurt less
- Keep your tires at the pressure on the door placard. An underinflated tire is much easier to pinch against the rim.
- Leave more following distance in spring, so you can see the road surface ahead instead of the bumper in front of you.
- Be suspicious of puddles. On a road you don't know, a puddle can be a deep pothole full of water.
- Low-profile tires on big wheels look good and suffer more. If you're buying winter wheels, going down an inch in rim size where the brakes allow it gives you more sidewall to absorb hits.
Reporting it
Potholes on city streets can be reported to 311. The City of Toronto also has a process for vehicle damage claims, but whether a claim succeeds depends on the circumstances, and there's a short deadline to file. If you're going to try, take photos of the pothole and the damage, note the exact location and time, and keep your repair invoice.
If you've hit something hard and the car doesn't feel right, bring it in. We'll check the tire, the wheel and the alignment, and tell you what we find before anything gets fixed.
