“When driving on the highway I notice there is a shake or shudder in my steering wheel. I don’t feel it under 80 km/h. It seems to get worse the faster I go.”

That was a question I recieved this week via email.

There are multiple components on modern vehicles that can result in a vibration in the steering wheel, and trying to find the exact source can challenge even the most experienced of mechanics. Also take into account the fact that multiple front end components could be worn out or out of alignment at the same time, and you will understand why the process of discovering the exact cause of steering wheel vibration can be a frustrating and time-consuming process.

There are 3 main areas I would examine, and in the following order: Tyre and Wheel Balance, Wheel Bearings and Suspension Setup. I would follow this order for two reasons; her symptoms seem to point to tyre and wheel balance issues, and you first want to rule out quick, easy, and cheap fixes. Obviously if the problem persists, you move onto the subsequent components.

Let us go through them one by one:

1.    Diagnosing tyre/wheel balance issues

 Easily the most common cause of steering wheel vibration is due to tyres and wheels that fall out of balance or become “unbalanced”. Tyre/wheel balance is the process of adding weight to the wheel after a new tire has been installed. Every tyre that comes off the factory floor has some imperfections in the construction or the weight distribution, and requires weights to counterbalance it.

The best way to determine if the steering wheel shaking is caused by your front tires and wheels being out of balance is to take your car in to any tyre fitment centre for “wheel-balancing”.

Typically, the warning signs that lead to this issue (many of which  Jing-Yu also noticed) include:

• The steering wheel vibrates when the vehicle reaches highway speeds (55 mph and above)
• The shaking progressively gets worse the faster the vehicle drives
• The shaking goes away when you decelerate below highway speeds

You can also perform some inspections yourself to determine whether your tyre/wheel balance is causing the steering wheel vibration.

Check the sides of your tires for marks. The most common cause of tires and wheels falling out of balance is due to the tyre striking an obstacle such a pothole or a curb. If you see scuff marks on the side of your tire, there is an increased likelihood that the tyre and wheel are out of balance. Colliding with an object will shift the weight balance of the tyre to where the tire struck the object.

Another simple check is to inspect the side of the wheel where the weights were initially installed. If you see a clean spot in the shape of a wheel weight on the side of your wheel, it is likely that the weight fell off. This check is hard to complete on the inside of the wheel, but if you can, turn the steering wheel to the extreme right/left and inspect the inside as well.

2: Diagnosing wheel bearing issues

The wheel bearings secure the wheel hub to the vehicle’s suspension. Inside the wheel bearing housing is lubricant designed to keep the bearings cool and reduce the buildup of heat as the wheel spins. Over time, the wheel bearings tend to lose lubricity, and if the bearings are not replaced in a timely manner, they can cause the wheel hub to loosen.

As the vehicle drives down the road, the loose wheel will vibrate, which may be felt in the steering wheel. If the wheel bearings are not replaced soon, they can break, causing the entire wheel/hub assembly to fall off the vehicle and create a dangerous driving situation.

There is a very simple test that any novice mechanic can perform to check whether the wheel bearings are causing the vibration. To perform this inspection, you will need to follow these basic steps.

1. Raise the front end of the vehicle on jack stands. Using a hydraulic lift or a jack and jack stands, raise the front end of the vehicle. Make sure to jack the front wheel from the lower control arm or the side body mount.

2. Check the tire/wheel for loose wheel bearings. As noted in the image above, the inspection for loose or worn out wheel bearings is rather simple to complete and is done by touch. Place both hands on the tire, preferably with one hand at 3 o’clock position and the other at 9 o’clock.

3. Push and pull the tyre in and out with both hands. If you do this and hear a clunking sound, or the wheel moves freely while shaking the tyre, the chances are good that the wheel bearings are worn out and need to be replaced.

4. Find a diagram or schematic representation of your vehicle’s hub and bearing. Within a few minutes of looking online, I was able to find the relevant Fortuner one (as shown below)

5. Log on to the Startmycar website from any device and have a look at our comprehensive range of bearings. Order before 8 am for same day delivery in Gauteng! If you are also in Durban, or any major city, RAM will have it at your door in 1-3 days.

6. Replace the wheel bearings or have a mechanic complete this task. If you have the right tools and experience, replacing the wheel bearings is a rather simple job to complete. 90% percent of the labour is getting the bearing carrier out. The remaining labour is pressing the new bearing in. A press greatly assists with this.

7. (In Jing-Yu’s case, i.e. a Toyota Fortuner, the hubs need to be replaced with the bearings as the fit as a unit.

If you do not have the necessary tools, or simply do not feel comfortable completing this task, contact a mechanic who can replace your wheel bearings for you. This is a dangerous situation that you do not want to delay fixing.

3: Inspecting suspension component issues 

There are multiple components that comprise the modern front end suspension. Each of these parts are connected to providing steering input, power the front wheels and keep the front wheel in line so the vehicle will drive straight down the road.

Improper alignment of suspension parts can impact the stability of the vehicle, and can also cause shaking in the steering wheel. The shaking is typically caused by suspension parts that are worn out or loose, which causes the alignment issues.

To find out if suspension parts are worn out or the suspension alignment is faulty, you will have to complete the following inspections:

• Check the tie rods for wear. The first items you want to inspect for wear and tear with regards to steering wheel vibration are the tie rods. Refer to your service manual for exact instructions and steps on how you should inspect them, as each vehicle's tie rod construction and location is unique.

• Check the bushings. A common cause of steering wheel vibration at lower speeds is when the bushings of the tie rods, spindles, or control arms are worn out.

Follow the steps below:

1. Jack up your vehicle's front end and place the front end on jack stands (make sure to put wheel chocks behind the rear wheels).

2. Using a flashlight or led inspection lamp, inspect the bushings for cuts, frays, pinching, signs of excess grease or the bushings being pushed out of the brackets. Try to move or wiggle the suspension part that is connected by the bushings. If the part moves, the bushings have failed and must be replaced.

3. Check the shocks, struts, and springs. Most vehicles have front struts or shock absorbers that are connected to the lower control arm and are a part of the suspension.

To check for wear and tear that could cause vibration in the steering wheel, complete the following inspections:

1. Look for signs of grease: When a shock or strut is leaking, you will usually find grease along the strut or the shock mounts. This could mean that the shocks or struts are loose, causing the vibration.

2. Check the spring for damage: In some cases, the spring will become detached from the coil-over shock/strut. This can also cause vibration issues.

3. Check the shock mounts: If the mounts are loose, it will cause the front end to rattle and steering wheel to vibrate. This is noticed immediately as soon as the vehicle moves forward or backward.

For all suspension related components, I would happily recommend the Teknosa range on the Start My Car website, as well as KYB for the Shock Absorbers/Struts. I have personally fitted both of these on my own vehicle. I replaced the lower control arms, bushes and tie rods with Teknosa parts at a fraction of the price the Nissan dealership quoted me. The quality is impressive and easily as good as the Nissan parts I took off. The KYB struts have made the car feel like new! The road-holding and damping is superb.

If you have completed all these checks and still can't find the source of the problem, I would recommend taking your vehicle in to a competent mechanic to diagnose the problem.