Five free practice questions on steering, suspension and wheels: block F of the Red Seal 310T Truck and Coach Technician exam, about 18 of its 135 questions. They are in the exam's format: four options, one correct answer. Answer each one before opening the explanation. No account, no email.
01The questions
-
A tractor's steer tires show a feathered, saw-tooth wear pattern across the tread, worse on one side. What steering fault does this pattern indicate?
- Under-inflation.
- Out-of-balance wheel.
- Incorrect toe setting.
- Excessive positive camber.
Show the answer
C. Correct. Feathering, where the tread blocks are worn to a sharp edge on one side and rounded on the other, is the signature of the tires scrubbing sideways as they roll, which is a toe error. The RSOS requires the technician to interpret tire wear patterns and lists toe among the geometry elements; bent tie rods and worn linkage that let toe change under load produce the same wear, so the linkage is measured before the toe is set.
Why not the others
A. Under-inflation wears both shoulders more than the centre, evenly and without feathering.
B. Imbalance produces cupped or scalloped wear spots around the circumference, not a saw-tooth across the tread.
D. Camber wears one shoulder of the tire smoothly, without the feathered edge across the tread.
-
A driver reports that a tractor sags on the left rear overnight and rises again after the engine has run a few minutes. The ride height valve was recently replaced. What is the most likely cause?
- A broken leaf spring.
- An air leak on the left side.
- The height valve is set too high.
- A worn shock absorber.
Show the answer
B. Correct. Sagging that recovers once the system builds pressure is air escaping from that side faster than the height valve can maintain it with the engine off: a leaking air spring, fitting, line or the new valve's connection. The RSOS lists sagging among suspension symptoms and soapy water among the tools; the technician pressurizes the system and soaps the left-side bag, lines and valve to find the leak.
Why not the others
A. A broken spring sags permanently; it does not recover when the compressor runs.
C. A high setting raises the truck all the time; it would not produce a sag that recovers.
D. A shock controls bounce; it does not hold the vehicle up and does not cause overnight sag.
-
A driver reports a shimmy in the steering wheel between about 80 and 95 km/h (50 and 60 mph) that disappears above and below that range. Steering linkage and king pins measure within limits. What is the most likely cause?
- A worn drag link.
- An unbalanced steer tire or wheel.
- Low power-steering fluid.
- Mismatched dual tires on the drive axle.
Show the answer
B. Correct. A shimmy that appears in a narrow speed band and clears above and below it is a resonance excited by an imbalance or a radial runout in a steer tire and wheel; it is the classic dynamic vibration the RSOS lists among tire, wheel and hub symptoms (shaking, shimmy, harmonic and dynamic vibrations). With the linkage good, the technician checks radial and lateral runout with a dial indicator, balances the assemblies, and inspects for a separated belt or a bent rim.
Why not the others
A. The linkage has been measured and is within limits, and drag-link play produces wander rather than a narrow-band shimmy.
C. Low fluid causes noise and heavy steering, not a speed-specific shimmy.
D. Drive-axle duals affect drag and heat; they do not shake the steering wheel in a narrow speed band.
-
While inspecting a trailer's kingpin with a wear plate gauge, a technician finds the gauge rocks on the pin and the pin's shoulder shows a visible step. What does this mean?
- The kingpin is worn beyond its limit and must be replaced.
- The kingpin needs lubrication.
- The gauge is the wrong size.
- The fifth wheel on the tractor needs adjustment.
Show the answer
A. Correct. The kingpin gauge is the go/no-go tolerance gauge NSC 11 Section 10 item 7(b) calls for; a pin worn more than 3.0 mm, or bent, deformed or repaired by welding, is rejected, and a stepped shoulder confirms wear past the limit. The RSOS lists the wear plate (for tolerances) among the tools and requires knowledge of hitch and coupler wear limits. A worn kingpin lets the jaws close loosely even when correctly adjusted, so the pin is the repair (replaced, or remanufactured only where a jurisdiction permits an engineer-certified process), not the tractor's fifth wheel.
Why not the others
B. Lubrication does not change the diameter of a worn pin.
C. Wear gauges are sized to the standard kingpin diameters; a gauge that rocks on the correct size indicates wear.
D. The gauge measures the trailer's kingpin. Adjusting the tractor's jaws cannot restore a worn pin.
-
A technician finds a hairline crack at a bolt hole in a tractor's frame rail during an inspection. What determines the next step?
- Whether the truck is due for a PM service anyway.
- Whether the driver has noticed a problem.
- Whether the shop has a MIG welder available.
- OEM procedure and welding certification rules.
Show the answer
D. Correct. Frame cracks are repaired only according to the manufacturer's service information, which specifies whether the rail may be welded, how the crack is prepared, what reinforcement is required and where holes may be drilled, and the RSOS requires the technician to identify the welding training and certification requirements for chassis repairs. A heat-treated rail welded outside that procedure fails again. The vehicle is out of service until an approved repair is completed, often by a specialty frame shop.
Why not the others
A. A frame crack is a structural defect that is addressed when found, not deferred to a schedule.
B. Cracks propagate without the driver feeling anything until the rail fails. The finding drives the action.
C. Equipment availability does not authorize a frame weld. The procedure and the certification do.
02Answer key
| Question | Answer | Sub-task |
|---|---|---|
| Q1 | C | Diagnoses steering systems |
| Q2 | B | Diagnoses suspensions |
| Q3 | B | Diagnoses tires, wheels and hubs |
| Q4 | A | Services hitches and couplers |
| Q5 | D | Diagnoses chassis/frames |
03What block F covers
This block covers steering, frames, suspensions, hitches, tires, wheels and hubs. It includes power steering gears and pumps, king pins and tie rods, alignment angles, frame cracks and modifications, air ride and leaf spring suspensions, torque rods and walking beams, fifth wheels, trailer kingpins and pintle hooks, dual tire matching, wheel nut torque and wheel bearing end play.
The Red Seal Occupational Standard names this block “Services, diagnoses and repairs steering, chassis/frames, suspensions, tires, wheels and hubs”. It carries 13.3% of the exam, about 18 of the 135 questions, split across five tasks. The share column is each task's weight within the block, as the standard publishes it.
| Task and its sub-tasks | Share of block |
|---|---|
| Services, diagnoses and repairs steering systems Services steering systems; Diagnoses steering systems; Repairs steering systems | 26% |
| Services, diagnoses and repairs chassis/frames Services chassis/frames; Diagnoses chassis/frames; Repairs chassis/frames | 14% |
| Services, diagnoses and repairs suspensions Services suspensions; Diagnoses suspensions; Repairs suspensions | 23% |
| Services, diagnoses and repairs hitches and couplers Services hitches and couplers; Diagnoses hitches and couplers; Repairs hitches and couplers | 15% |
| Services, diagnoses and repairs tires, wheels and hubs Services tires, wheels and hubs; Diagnoses tires, wheels and hubs; Repairs tires, wheels and hubs | 22% |
04What the questions turn on
Wheel bearing end play
End play is read with a dial indicator on the hub while the wheel is pushed and pulled along the axle centreline. With no manufacturer's figure, NSC 11 accepts 0.02 to 0.13 mm (0.001 to 0.005 in). Too tight overheats the bearing.
Reading steer tire wear
Feathered, saw-tooth wear across the tread means the tire is scrubbing sideways, which is a toe error, so measure the linkage before setting toe. Cupped, scalloped wear means the tire is bouncing from worn shocks or an imbalance.
Ride height sets angles
Air-ride height is measured at the manufacturer's reference points with system pressure up, then the height-control valve is adjusted to suit. A valve set high or low changes the u-joint working angles and can bring on a driveline vibration.
Fifth wheel slack
A clunk on every start and stop, with the trailer shoving, is jaw-to-kingpin slack. Measure and adjust the lock, but gauge the trailer kingpin too: a pin worn more than 3.0 mm lets correctly adjusted jaws close loosely and must be replaced.
05The other blocks
The 310T exam has 11 blocks. Each has its own page of free questions:
The 310T Truck and Coach Technician practice exam page describes the full question bank. How these questions are written and checked: how our questions are made. Found a mistake? Tell us and we will fix it.