Suspension, Steering & Alignment
Rides right. Handles right. Wears right.
Suspension, Steering & Alignment covers the chassis systems that keep vehicles safe and comfortable. Includes basic alignment theory even though most mobile mechanics don't do wheel alignments themselves. Everything below is free, no login, no paywall. Work through the skill areas, drill them in Study Mode, and when you're ready, prove it with the certification exam.
Your readiness to certify
Drill all 60 concepts in Study Mode. Mark each one "Got it" once you know it cold. When every concept is cleared, you're ready for the SUS exam.
What you'll be able to do
- Strut and shock diagnosis and replacement
- Control arms, ball joints, tie rods, sway bar links
- Rack and pinion service, power steering diagnosis
- Wheel bearings and hubs
- Alignment theory: caster, camber, toe, thrust angle
- Ride height and adjustable suspension systems
- CV axles and driveline vibration diagnosis
Skill areas
18 lessons, each one short enough to finish in a break. Every lesson teaches the system from the ground up, ends with a call to work, and tracks which concepts you have cleared.
Fundamentals
Before you can diagnose a clunk or dial in an alignment, you need to be clear on what the suspension is actually there to do.
Alignment
Alignment is where suspension geometry meets the real world of tire wear, pulls, and off-center steering wheels.
Shocks & Struts
Dampers are the most misunderstood parts on the car.
Ball Joints
Ball joints are the pivots that let the wheel steer and the suspension travel at the same time.
Tie Rods
Tie rods are the last link between the steering gear and the wheels.
Wheel Bearings
Wheel bearings hum along invisibly until they don't, and then they announce themselves with a growl that changes with load.
Springs
Springs set the ride height and store frightening amounts of energy doing it.
Sway Bars
The sway bar doesn't hold the car up and doesn't absorb bumps.
Control Arms
Control arms locate the wheel, and their bushings are the quiet rubber parts that decide whether the arm moves precisely or sloppily.
Power Steering
Power steering has split into two worlds: hydraulic systems with pumps and fluid, and electric systems with torque sensors and software.
Steering Rack
The rack-and-pinion is the heart of most modern steering systems, converting steering wheel rotation into side-to-side tie rod movement.
Tires
Tires are the suspension system's report card — every alignment error, worn damper, and balance problem eventually writes itself into the tread.
Steering
Steering complaints arrive as noises, wanders, and vague descriptions — and several of the classics aren't even steering problems.
Diagnostics
Chassis diagnosis is pattern recognition: speed ranges, load conditions, and noise character each point to a short list of causes.
Fasteners
Suspension work lives and dies by fasteners and pressing technique.
Suspension Types
Suspension architecture determines how the wheel moves through its travel.
Safety
Suspension parts fail differently from most car parts: when they let go, they let go all at once, at speed, with the driver aboard.
Regulation
On commercial vehicles, suspension condition isn't a judgment call — it's regulated.
Studied the material? Get SUS certified.
The Suspension, Steering & Alignment exam turns what you just learned into a verifiable credential drivers and shops can look up. 45 questions · 60 minutes · 75% to pass · Free.
Studying on MechanicRank is free forever. There's no obligation to take the exam.
The work these lessons teach.
Real jobs from Supercanic trucks — the systems above, out in the field.
Real-world cost guides for this system.
See what customers pay for the jobs this track teaches, parts, labor hours, and state-by-state ranges from our repair cost estimator.
Standards and further reading
Primary sources behind this page. Federal safety, emissions and consumer-protection references, worth reading before you authorize any repair.
- NHTSA TireWise Federal guidance on tire age, load ratings, pressure and tread depth.
- ASE certification The national standard for automotive technician testing and certification.
- SAE International The engineering body behind fluid, fastener and diagnostic standards.
- California Bureau of Automotive Repair Licensing, consumer complaints and shop regulation in California.