ASE A4 wheels and tires practice questions.

Five free practice questions on wheels and tires: content area D of the ASE A4 Suspension & Steering test, 5 of its 40 scored questions (12.5%). They are in the ASE format: four options, one best answer. Answer each one before opening the explanation. No account, no email.

01The questions

1. Recall · Wheel and Tire Diagnosis and Service

   The Tire Identification Number that follows the letters DOT on a tire's sidewall ends with the four digits 2319. What do those four digits tell the technician?

   1. It should be replaced by week 23 of 2019
   2. It was made in the 19th week of 2023
   3. It was made on February 3, 2019
   4. It was made in the 23rd week of 2019
   Show the answer

   D. Correct. Federal rules make the last four digits of the Tire Identification Number the date code: the first two give the week of manufacture and the last two the year. Reading it shows a tire's age, which matters when the vehicle or tire maker sets an age limit.

   Why not the others

   A. The digits are a manufacture date, not an expiry date. 2319 means the tire was made in the 23rd week of 2019; any replacement age comes from the vehicle or tire maker.

   B. This reads the code backward. The first two digits are the week and the last two are the year, so 2319 is the 23rd week of 2019.

   C. The code is not a month and a day. Its first two digits are the week of the year and its last two the year, so 2319 means the 23rd week of 2019.

2. Recall · Wheel and Tire Diagnosis and Service

   A car's four identical tires have an asymmetric tread, with one sidewall marked 'outside' and no rotation arrows, and they are mounted on four identical wheels. Which statement about rotating them is correct?

   1. They can be mounted with either sidewall facing out
   2. They can move only front to rear on the same side
   3. They must be remounted on the wheel to change sides
   4. They can move to any position without remounting
   Show the answer

   D. Correct. An asymmetric tread works in either direction of rotation; it only needs its marked sidewall facing outboard. The wheels' outer faces stay outboard at every corner, so the assemblies can go to any position, side to side included, as mounted.

   Why not the others

   A. The 'outside' marking means the tread is designed for that sidewall to face outboard, so mounting it the other way round is wrong. Mounted correctly, the assembly can then go to any position.

   B. Front to rear on the same side is the rule for directional tires marked with rotation arrows. These tires have no arrows; an asymmetric tread can go to any position while its 'outside' sidewall faces out.

   C. Remounting to change sides is needed only for directional tires, so they keep turning the marked way. An asymmetric tire keeps its 'outside' sidewall outboard on either side of the car, so no remount is needed.

3. Recall · Wheel and Tire Diagnosis and Service

   A wheel and tire assembly's radial runout, read on the tread, exceeds the manufacturer's limit. Which measurement shows how much of that runout comes from the wheel?

   1. Lateral runout of the hub mounting flange
   2. Lateral runout of the tire on its sidewall
   3. Radial runout at the wheel's bead seats
   4. Radial runout of the tread after rebalancing
   Show the answer

   C. Correct. The tire's beads sit on the wheel's bead seats, so radial runout measured there on the bare wheel shows the wheel's share. Comparing it with the assembly reading tells whether to match-mount the tire or replace the wheel or the tire.

   Why not the others

   A. Hub flange lateral runout tilts a wheel; it does not show the wheel's out-of-round. The wheel's share of radial runout is read at its bead seats.

   B. Lateral runout is side-to-side wobble and answers a different question. The wheel's share of radial runout is read as radial runout at its bead seats.

   D. Balancing corrects weight, not shape, so the tread runout reads the same after it. To separate wheel from tire, read radial runout at the wheel's bead seats.

4. EXCEPT · Wheel and Tire Diagnosis and Service

   Right after two used tires are fitted to the front, a pickup pulls to the right on a straight, level road while cruising. The alignment is within specification and equal side to side, and the brakes release freely. Any of these tire conditions could cause the pull EXCEPT:

   1. a left front tire of smaller diameter than the right.
   2. lower pressure in the right front tire than the left.
   3. a front tire with its belt built off-center (conicity).
   4. front tires of two different tread designs.
   Show the answer

   A. Correct. A tire of smaller diameter rolls like the small end of a cone and draws the vehicle toward its own side, so a smaller left front tire would pull the truck to the left, not the right. Lower right front pressure, conicity and mismatched tread designs can each pull to the right.

   Why not the others

   B. A softer right front tire has a smaller rolling radius and more drag, so it draws the truck to the right and could cause this pull. The exception is the smaller left front tire, which would pull to the left.

   C. An off-center belt makes a tire roll like a cone and push the truck to one side even with correct alignment, so it could cause this pull. The smaller left front tire is the exception, since it would pull to the left.

   D. Tires of different construction or tread design on one axle can make unequal cornering and rolling forces, so the pair could pull the truck to one side. The exception is the smaller left front tire, which pulls left.

5. Recall · Wheel and Tire Diagnosis and Service

   A front wheel and tire assembly balances to zero on a conventional spin balancer, but the car still shakes at 60 mph. What can a road-force balancer measure that a spin balancer cannot?

   1. Couple imbalance that makes the tire wobble
   2. Static imbalance that makes the tire hop
   3. Tire stiffness variation under load
   4. Imbalance in the hub and brake rotor
   Show the answer

   C. Correct. A road-force balancer presses a roller against the spinning tire and measures how the force changes around it, finding a tire that is stiffer or taller in one spot even though it balances. It can then show where to turn the tire on the wheel to match-mount it, or that the tire needs replacing.

   Why not the others

   A. A two-plane spin balancer measures couple (dynamic) imbalance as well, and the assembly balanced to zero. The road-force machine adds a loaded roller that finds stiffness variation.

   B. A spin balancer measures static imbalance already, and this assembly reads zero. What it cannot see is how the tire's stiffness varies when loaded, which the road-force roller measures.

   D. A road-force balancer tests the wheel and tire off the vehicle, so it never sees the hub or rotor at all. What it adds over a spin balancer is measuring tire stiffness variation under load.

02Answer key

03What area D covers

This content area covers tires and wheels and how they affect the ride. Questions deal with tire wear patterns and sidewall markings, load and speed ratings, inflation pressure, vibration, shimmy and pull, rotation patterns and lug nut torque, radial and lateral runout, mounting and balancing, puncture repair limits, and direct and indirect tire pressure monitoring systems.

The ASE test specification calls this content area “Wheel and Tire Diagnosis and Service”. It carries 5 of the 40 scored questions, 12.5% of the test.

• Read tire wear patterns and sidewall markings
• Check tire size, load and speed ratings
• Set inflation pressure to the placard
• Diagnose vibration, shimmy, noise and pull
• Rotate tires and torque wheel fasteners
• Measure wheel, tire, hub and flange runout
• Mount, dismount and balance tire assemblies
• Service and relearn direct and indirect TPMS

04What the questions turn on

Wear patterns point to causes

Both shoulders worn more than the center points to low inflation, and center ribs worn first to too much pressure. Diagonal patches repeating around the rear tires of a front-wheel-drive car point to a rear toe error.

Trace runout to its part

If the high spot stays at the same stud after the wheel is moved on the hub, the runout is in what the wheel bolts to, such as the axle flange. A true rim with a wobbling sidewall puts the fault in the tire.

Static versus couple imbalance

Two equal heavy spots on opposite sides and in different planes form a couple that wobbles the wheel and shimmies the steering. One weight can cancel the up-and-down force yet leave that couple, so wide assemblies are balanced in two planes.

Pressure follows temperature

The gas law works in absolute values: add 14.7 to gauge pressure and 460 to the Fahrenheit temperature before calculating. Tires set to placard pressure in a warm shop therefore read low once the vehicle sits outside in cold weather.

05The other content areas

The A4 test has four content areas. Each has its own page of free questions:

The ASE A4 Suspension & Steering practice test 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.

ToolboxPrep is an independent study site. It is not affiliated with or endorsed by ASE (the National Institute for Automotive Service Excellence). Our questions are original practice questions written to the published ASE test specifications; they are not actual test questions.