The chassis is the backbone of your truck. Everything else bolts onto it: the cab, the engine, the transmission, the axles, the body. When the frame has a problem, the whole truck pays the price.
At Ressorts Industriels Laval / C.T. CAM, chassis repair and modification has been our core work since 1971. Here’s a complete look at the types of damage we handle, how we repair them, and what Quebec law requires.
Types of Chassis Damage
Fatigue Cracks
Fatigue cracks are the most common type of frame damage. Metal accumulates stress over thousands of load cycles, and eventually develops micro-fractures that grow into visible cracks. These cracks appear most often at stress concentration points: around bolt holes, at the junctions between frame rails and crossmembers, and at locations where accessories are bolted directly to the rail.
A fatigue crack starts small. Without repair, it propagates with every kilometre driven. We regularly see cracks that began as a 2-inch hairline and were left to grow into 2-foot splits before the owner brought the truck in.
Overload Cracks
Running over rated capacity repeatedly puts the frame under bending stress it was never designed to handle. Overload cracks tend to be wider and deeper than fatigue cracks, and usually appear at mid-span on the frame rail where flexion is greatest under load.
⚠️ Attention
A frame crack is not a repair you postpone until next week. The more the truck is driven with an active crack, the larger it grows. What can be fixed with an $800 weld today may require an $8,000 section replacement in three months. It is also an automatic SAAQ inspection failure.
Corrosion Damage
Quebec road salt and calcium chloride are relentless on steel frames. Rust compromises the metal’s load-carrying ability even without a visible crack. Advanced corrosion can reduce a frame rail to the point where it crumbles rather than holds. This is one of the most insidious types of damage because it often progresses out of sight on the inner face of the rail.
Impact Damage
A serious pothole, an off-road incident or a collision can bend, twist or crack a frame rail in one event. Impact damage is often the most severe because it affects the overall geometry of the chassis, not just a localized section.
Repair Techniques We Use
Crack Welding
Welding is the standard method for repairing a frame crack, but welding a truck frame is not the same as welding a fence post. Heavy truck frame steel is high-strength alloy material that responds differently to heat than mild steel.
Our process:
- Map the full extent of the crack by cleaning the metal and doing a thorough visual inspection
- Drill a stop-hole at each end of the crack to prevent further propagation during and after repair
- Bevel the crack edges to allow full-depth weld penetration
- Weld using the correct process matched to the steel grade and rail thickness
- Grind and inspect the completed weld for voids or porosity
We never weld a cold frame. Pre-heating the steel before welding is essential to prevent hydrogen-induced cracking in the heat-affected zone.
Reinforcement Plates
When a section of the frame is too weakened for welding alone, we install a reinforcement plate. This is a steel plate bolted or welded over the damaged area to redistribute load around it. Reinforcement plates are also installed preventively at known stress points when a truck is being converted to a heavier duty application.
Section Replacement
In cases of severe corrosion or major impact damage, we cut out the damaged section of the frame rail and weld in a new section of matching steel. This is the most labour-intensive repair, but sometimes the only correct option.
Chassis Modifications
Beyond repairs, chassis modification is one of our most requested services from commercial fleet operators.
Frame Extensions
Adding length to accommodate a larger body, a longer wheelbase, or additional equipment. We cut the frame, insert the new section and weld to manufacturer specifications.
Frame Shortening
Converting a long-wheelbase highway truck to a shorter urban delivery configuration. Less common, but we do it.
Wheel Conversions
Converting a 6-wheel truck to a 10-wheel configuration, or the reverse. This involves modifying axle mounts, frame reinforcements and sometimes frame length. It also changes the vehicle’s class and requires an engineer’s report.
Equipment Mounting
Installing cranes, winches, hydraulic arms or other specialized equipment on the frame. Every installation must respect the frame’s rated capacity and the vehicle’s weight distribution.
SAAQ Certification Requirements
In Quebec, any structural modification to a heavy truck chassis must be accompanied by an engineer’s report. This document confirms that the modification meets applicable safety standards and that the frame can support the intended loads.
After modification, the vehicle must be re-plated with a new GVWR if the class has changed. A SAAQ mechanical inspection then confirms full compliance.
At Ressorts Industriels Laval, the engineer’s report, SAAQ certification and re-plating are all included in our modification service. You bring us a truck with a project, and it leaves certified and road-ready.
Chassis Repair Costs
| Repair | Typical Price Range |
|---|---|
| Simple crack weld | $500 to $1,500 |
| Weld with reinforcement plate | $1,000 to $3,000 |
| Section replacement | $3,000 to $8,000 |
| Frame extension | $5,000 to $15,000 |
| Frame shortening | $4,000 to $10,000 |
| 6-to-10 wheel conversion | $8,000 to $20,000 |
💡 Any structural modification to a heavy truck chassis in Quebec requires an engineer’s report. Without that document, the modification is not recognized by the SAAQ and the vehicle cannot be re-plated. Make sure the shop doing the work can provide this report.
All prices include parts, labour and, for modifications, the engineer’s report. Exact cost depends on truck model, steel specifications and project complexity.
How to Inspect Your Own Chassis
A basic visual inspection takes ten minutes and can catch problems early:
- Get under the truck with a flashlight. Look for cracks, heavy rust and deformation along the full length of both frame rails
- Check stress points: around suspension mounting bolts, crossmember junctions, and anywhere accessories are attached
- Look for rust that flakes when touched. If the metal crumbles under light finger pressure, the corrosion is advanced
- Check that the truck sits level. View from the rear: both sides should be the same height
If you spot anything unusual, have it professionally inspected. Our article on when to repair a truck chassis provides more guidance on what warrants immediate action vs monitoring.
What We Do at Ressorts Industriels Laval / C.T. CAM
When you bring your truck to us for a chassis repair or modification, we perform a complete assessment, including:
- Full visual inspection of the chassis (frame rails, crossmembers, mounts)
- Dye penetrant testing when needed to detect hidden cracks
- Welding performed to standards for high-strength steel
- Installation of reinforcement plates at identified stress points
- Engineering reports and SAAQ certification for any structural modifications
- Vehicle re-registration if the class changes
We only repair what actually needs to be repaired. We explain what we found, provide you with a price before any work begins, and back our work with a one-year warranty on parts and labor.
Frequently Asked Questions About Truck Chassis Repair
Can any welder repair a truck frame?
Most frame rails, yes, but the process and filler material must match the steel grade. High-strength frame steel requires specific procedures that a general welder may not be set up for. Chassis work needs to go to a shop that specializes in heavy trucks, not a general fabrication shop.
Is a frame crack dangerous?
Yes. An unrepaired crack will grow under load. In a worst-case scenario, the rail fails completely. It also results in an automatic SAAQ inspection failure.
How long does a chassis repair take?
A straightforward crack weld typically takes one to two days. A frame extension or full conversion can take one to two weeks depending on complexity. We give you a realistic timeline before we start.
Are chassis repairs covered under a warranty?
At our shop, yes. We offer a one-year warranty on chassis repair work. If the weld fails during the warranty period, we redo it at no charge.
Can I drive to your shop with a cracked frame?
It depends entirely on the crack size and location. A small crack on a secondary crossmember can wait a few days. A crack on a main frame rail cannot. Call us, describe the location and size, and we’ll tell you whether it’s safe to drive in or whether the truck needs to be towed.
Does worn [suspension](https://www.ril-ctcam.com/services/suspensions/) cause frame damage?
Absolutely. Worn suspension transfers more impact energy directly into the frame instead of absorbing it. Broken or loose U-bolts create load concentrations that initiate cracks. We always inspect the suspension at the same time as the chassis.
Related pages and articles
Chassis Work Is What We Do
Frame repair has been in our DNA since 1971. From a hairline crack to a full conversion with engineer’s report and SAAQ certification, we have the equipment and expertise to handle it.
Call us at 450-661-5157.