Road Force Balancing Fixed a 2025 GMC Sierra AT4 Highway Vibration (Calgary Case Study)
A customer brought his 2025 GMC Sierra AT4 into Prince Tires with a vibration that kicked in around 80 km/h and stayed with him all the way to 120 km/h. Brand new truck, good tires, already balanced, and it still shook on the highway. We put all four wheels on our Hunter Road Force balancer, force-matched every tire to its rim, and took the truck out on the highway with him at 109 km/h. Smooth. He was happy, and so were we.
Here's exactly what we found and what we did, with the photos and video from the job.
The job at a glance
- Vehicle: 2025 GMC Sierra AT4 on aftermarket wheels with Toyo Open Country all-terrain tires
- Complaint: vibration between 80 and 120 km/h
- Diagnosis: all four tire and wheel assemblies tested on a Hunter Road Force balancer
- Fix: old weights removed, each tire force-matched on its wheel, then re-balanced
- Final Road Force readings: 5, 7, 9 and 19 lb, all under the light-truck limit
- Result: test drive with the customer at 109 km/h, no vibration
The problem: a shake that wheel weights couldn't fix
When we pulled the wheels off, the first thing we noticed was how much weight was already stuck on them. Someone had tried to balance the vibration out, and the wheels were carrying stacks of stick-on weights.
That's a common sign the problem isn't weight at all. A regular balancer only answers one question: is this wheel heavier on one side? But a tire can be perfectly balanced and still have a stiff spot, or a high spot where it's slightly out of round. You can't fix that with weights. On the highway, that spot hits the road once every turn of the wheel, and at 100 km/h that's a lot of hits per second. That's the shake you feel in the steering wheel or the seat.
Big all-terrain tires on a heavy truck like the Sierra AT4 make this worse. Stiffer sidewalls and heavier assemblies mean small differences show up as real vibration.
What Road Force balancing does differently
Road Force balancing tests the tire the way it actually lives: under load. While the wheel spins, a big roller presses against the tread, standing in for the road and the weight of the truck. The machine measures how hard the tire pushes back all the way around. If one spot pushes back harder, that's your vibration, and now we can see it as a number.
At the same time, a laser scans the wheel itself, so the machine knows whether the problem is in the tire, the rim, or both.
What we did, step by step
- Stripped the old weights. Every old weight came off so we could see what each assembly was really doing.
- Tested all four tires on the Hunter. Each wheel and tire went on the balancer for a full Road Force and runout measurement.
- Force-matched each tire to its wheel. Every rim has a low spot and every tire has a high spot. We rotated each tire on its rim so the tire's high spot lines up with the wheel's low spot, and they cancel each other out instead of adding up.
- Re-measured and re-balanced. After matching, we checked the Road Force again and balanced each wheel with fresh weights, much less than what was on there before.
- Reinstalled and torqued the wheels. Then we went for a drive.
The numbers: 5, 7, 9 and 19 lb
After force matching, the four tires came in at 5, 7, 9 and 19 lb of Road Force. Lower is better, and the Hunter compares every reading against limits for the type of vehicle. Light trucks like the Sierra are allowed a higher number than a car, and all four of this truck's tires came in under that light-truck limit, with three of them well under.
The test drive
We don't hand the keys back and hope. We took the truck out on the highway with the customer in the passenger seat and ran it through the speed range where it used to shake. At 109 km/h the truck was smooth. No steering wheel shimmy, no seat vibration. The customer was happy with how it drove, and that's the whole point.
Signs you need Road Force balancing
- A vibration that shows up at highway speed, often somewhere between 80 and 120 km/h
- The steering wheel shakes, or you feel it through the seat or floor
- You've had your tires balanced, maybe more than once, and it's still there
- Lots of stacked wheel weights on your rims
- New tires, new wheels or a lifted or levelled truck, and the ride hasn't felt right since
- Large all-terrain or mud tires on a pickup or SUV, like the 37-inch Cooper STT Pros we Road Force balanced on a lifted Ram 3500 dually
When balancing won't fix it
Not every vibration is a tire problem, and we'll be straight with you about that. A bent wheel, worn suspension or steering parts, a driveline issue or a brake rotor problem can all feel similar. If the vibration only happens when you brake, for example, that points to the brakes, not the tires. Road Force testing helps here too: if all four assemblies measure clean and the truck still shakes, we know to look somewhere else, and you haven't wasted money guessing.
FAQ: Road Force balancing in Calgary
What is Road Force balancing?
Road Force balancing spins your wheel and tire on a Hunter balancer while a load roller presses against the tread, like the road does under the weight of your vehicle. It measures how evenly the tire pushes back all the way around, not just whether it's heavy on one side, so it finds vibration causes a regular balancer can't see.
What's the difference between Road Force and regular balancing?
A regular balancer only finds weight imbalance and fixes it with wheel weights. Road Force balancing also measures stiff spots and out-of-round in the tire and wheel under load. Those can't be fixed with weights, which is why a tire can be "perfectly balanced" and still shake on the Deerfoot.
Will Road Force balancing fix a vibration at highway speed?
If the vibration is coming from the tires and wheels, usually yes. A shake that shows up around 80 to 120 km/h and changes with speed is the classic sign. If the cause is a bent wheel, worn suspension or a driveline part, balancing won't fix it, and we'll tell you that.
What's a good Road Force number?
Lower is better. The Hunter compares each tire against limits for your vehicle type, with light trucks allowed a higher number than cars. On this Sierra AT4 we finished at 5, 7, 9 and 19 lb, all under the light-truck limit.
Where can I get Road Force balancing in Calgary?
Right here at Prince Tires. Give us a call and we'll book you in.
Truck shaking on the highway? Bring it in.
If your truck, SUV or car vibrates at highway speed and regular balancing hasn't fixed it, call us to book a Road Force balance. Every install also comes with a free re-torque check.
Prince Tires – South
111 42 Ave SW, Calgary
(403) 452-4283
Prince Tires – Northeast
3928 Edmonton Trail NE, Calgary
(825) 395-4024
Open Monday to Saturday 9 to 5, Sunday 10 to 2. Shopping for new tires too? Browse our prices at princetires.ca.
Posted by the Prince Tires team, November 2026.
