- 6 Min Read
- By: Noah Jenkins
Diagnosing Steering Wheel Shake And Vibration
A steering wheel shake, vibration, (or a shimmy) can make for an undesirable and frankly annoying time in your car. You may find yourself dreading having to get on the highway for any length of time - we've all been there! Steering wheel shake can be caused by a few different things and some can be addressed very quickly and have you back on the road with a vibration-free ride.
If there is a shake in your wheel, you can begin to pinpoint the problem to the front end of the vehicle. There are many bushings, joints and other items designed to help with the handling of your vehicle which, over time, can wear leaving "play" in them and ultimately that unwanted vibration. There are a few steps you can take to help narrow down the root cause of your vibration.
The summer is here in full force and that means road trip season. If your car's steering wheel is shaking on a short journey, you may be hesitant to take it out on a much longer drive. The steps below will help you determine if your steering wheel shake is a safety concern or if it's just going to annoy you on your upcoming drive.
Why does my steering wheel shake?
It's all too common for us to look beyond the simple solutions when diagnosing problems with our cars. I found this especially true on a few occasions when my car developed a vibration. Before you start throwing parts at your car, do the following:
- Check to make sure your tire pressures are correct per the manufacture recommendations.
- Tire pressures play a larger role than you might imagine. A severely underinflated tire not only could cause jarring shaking, but is also a blow-out hazard. Most tire blow-outs happen from underinflated tires and not over-inflation.
- Check to make sure your lug nuts are tight, and properly torqued.
- If you just installed your wheels or went to a tire shop, this is very important. It's common for these places to install your wheels using an impact gun. We recommend torquing your lugs to manufacturer's spec any time you have your wheels off the car. Beyond that, you should check them after 20-50 miles of driving as they can loosen up.
- Check and make sure your Volvo axle nuts/bolts are tight and properly torqued.
- If your car has been sitting for a little bit, especially in the cold, the tires may have developed flat spots on them. Give them time to warm up and reshape and see if your vibration goes away.
- Check your rims for any cracks or bends on the inside.
- This is often overlooked. The inside of your wheel is just as susceptible to damage as the outside. If you have a vibration, you should remove your wheels and inspect for dents or cracks.
If after ruling out the simple fixes your vibration still persists, only then is it time to look more in depth at your situation.
Figure out when the steering wheel shake occurs
Start by driving your vehicle under a few different conditions to determine if it occurs at: low speeds, highway speeds, while accelerating, while braking, at standstill idle, or when turning left/right?
It may also be happening under multiple instances such as accelerating and highway speeds. Knowing this will help you eliminate certain items. For example, if your steering wheel has a slight vibration at idle but not under any other circumstances it's not going to be a wheel balance issue or a bad tie rod end (or anything suspension related for that matter).
Once you have determined when the vibration occurs, try and replicate it and make a mental note of specifically when it starts and when it goes away. In some cases, it may be progressive. Prior to replacing my tie rod ends, my Volvo S70 had a vibration which seemed to get worse from 70mph+, this would be a progressive vibration. Or, lets say you had a bad wheel vibration when braking lightly from high speeds, but if you pressed the pedal harder, it would go away...this would also be a progressive vibration.
Steering wheel shake at low speed or idle
If you have a steering wheel vibration at idle or under light acceleration, this is most likely your engine mounts which have worn a bit. More often than not, this is not a serious issue provided its not hand-shaking-bad! My S70 had a upgraded polyurethane engine upper torque mounts. Vibration at idle was completely normal due to the stiffer nature of the mount. If you have a P80 or P2 Volvo, begin by replacing your upper engine mount and transmission torque mount. These are both relatively easy to replace a not too expensive. Again, keep in mind if you decide to use the upgraded polyurethane mounts, you may notice the same amount of vibration if not more!
Steering wheel shake while braking
As your brakes wear, if low-quality pads/rotors are used, many cars can become a victim of a steering wheel vibration/shimmy while braking. It's usually most significant when braking from a high speed like on highway off-ramps. To find out if this is the issue, first pull off your front wheels and inspect your front brakes. You should be looking for any sort of "lip" on the rotor. Also, look at your pads and see much of them are remaining. If your brakes are well worn, then you should simply replace both the pads and rotors. Since they need replacement anyway you will be "killing two birds with one stone." Then you'll have fresh brakes and your shimmy should be resolved.
Beyond pads, your brake rotors can warp and become "untrue" and will wobble. This can happen from improper bedding or using new pads on old rotors or vice versa. I always stress doing rotors and pads at the same time and properly bedding them to prevent this.
You may also have a bad caliper which is causing this improper wear on your pads and rotors. Check the caliper by attempting to retract the piston(s). They should go back smoothly and evenly. If excessive force is required to push the piston back in, or brake fluid leaks from around the boot. You need to replace the caliper or else your new brake parts will end up just like the old ones!
Steering wheel shake while accelerating
Acceleration places a load on your axles which is greater than when you are cruising. A friend of mines car developed quite a violent vibration only under acceleration onto a highway entrance ramp. The problem was one of his axles which had developed a tear in the inner boot causing the grease to leak out and the joint became dry and therefore could not work smoothly.
Get your car up on jack stands and pull the wheels off. Grab onto your axle and see if there is any excessive play in it (also will cause vibration). Next inspect the boots. If one or both of the boots has torn and it's apparent there isn't any grease left, you may need to replace the axle. However, if there is a small tear and the joint has not gone completely dry, I would try repacking the joint and installing a new CV boot as the joint may be able to be saved.
Note: On rear wheel drive cars and some all wheel drive cars, you may notice a vibration felt through the whole car under acceleration, this could mean that your driveshaft is imbalanced. This was the case with a 1998 V70R AWD I worked on.
Steering wheel shake when driving at high- speeds
A vibration felt in your steering wheel at high-speeds (think highway speeds) can almost always be a wheel balance issue. If this is the case, take your wheels to be balanced and rotated. Wheels are balanced with weights placed either on the inside of the wheel or on the outer lip. This service is not at all expensive and always a good place to start. If your wheels cannot be balanced, they may be untrue and require a replacement. If after balancing and rotating your wheels, you still find there to be a vibration, now is time to inspect your suspension components.
Start by jacking up the front end of your car so both front wheels are off the ground.
Next, get a hold of your wheel at two positions across the diameter of the wheel and give it a good shake. The wheel should not move. If it does, inspect further.
Next, remove your wheel and inspect all of the joints and bushings and look for cracks and tears in the rubber. Also, grab the individual suspension components such as your control arms see if you can shake them. Take a careful look at the tie rods. Grab them and see if you can rotate them with your hand. If you can, the joint is bad and requires replacement. Tie rod and tie rod ends are one of the biggest culprits of steering wheel shake and should be inspected almost immediately.
Steering wheel shake while turning left or right at speed
What I mean by turning left or right at speed is a situation when you are turning on a sweeping turn at speeds above 35 mph or so. Though rare, sometimes a vibration can be felt when one side of a vehicle becomes "loaded" (weight is transferred to one side). This increases the force placed on one side of the vehicle and all its suspension components. In my experience, a bad wheel bearing can be blamed for this. A bad wheel bearing has other symptoms though such as a loud groan or in some cases a grinding noise.
Steering wheel shake and vibration doesn't have to be a dreaded issue if you take the time to narrow down the potential causes one by one. Before jumping to conclusions and assuming the worst, it could be something as simple as a wheel that has lost wheel weights.
If you have any suggestions on how else to diagnose wheel and chassis vibrations, or if you have any questions about yours specifically, be sure to leave them in the comments section below.