Updated at: 20-08-2022 - By: Lucas

The car shuddering at speeds beyond 30 miles per hour is quite alarming and should be addressed immediately. Even if it doesn’t seem like a big deal, persistent vibrations can lead to increased part wear and failure, which can lead to a loss of control over the vehicle.

If you want to avoid this, study the following list and determine the root cause before an accident occurs. This list will cover every conceivable source of swaying, trembling, or other strange noises in a vehicle.

1. Tires

Car Vibrates Between 30 And 40 Mph (1)

One sign of tire trouble is interior rattling, and this can be caused by a variety of factors.

Tire wear

Tire deterioration is one of the most common culprits. After a certain number of years or kilometers, tires need to be replaced. You’ll need a micrometer caliper if you want to measure the tread on your tires.

Short version: The underside of the caliper’s protruding spike serves as a depth measuring device. Before letting the spike fall into the tread of the tire, check the calibration and measurement mode on the digital display. It is illegal to drive on tires with a tread depth of less than 4mm or 0.15 inches.

Although it might not be obvious, slanting tires can lead to uneven wear on one side of the car. Check for differences in tread depth by measuring the tire’s breadth.

Winter tires

Because winter tires’ rubber isn’t made to perform well in warmer climates, they also produce needless vibrations. Look for a snowflake emblem or M+S marking on the side of the tire to determine whether or not it is a winter tire. Winter tires can be used in the summer, but they’ll perform worse, wear out faster, and be less comfortable to drive on.

Unbalanced tires

A minor unbalance will result from the combination of these two large items, as neither the tire nor the rim are perfect. This causes the steering wheel and the floor to tremble.

When a tire gets flat, travels a long distance, or begins to vibrate, it’s important to have it balanced before it’s mounted on the rim. Wheel weights are clipped to the rim’s edge by tire specialists after they’ve identified the unbalanced places using special machinery. If you can’t recall the last time you had your tires balanced, have your vehicle inspected by a professional tire shop.

2. Wheels

For some reason, the terms “tire balance” and “tire alignment” are used interchangeably. The geometry of the tires on the rim is important for tire balancing, but the angle of the wheel itself is more important for tire alignment.

The rattling or vibrations you’re feeling are the result of misaligned wheels wearing out your tires faster, reducing your vehicle’s stability and handling. Wheel alignment is a job best left to the experts, as it necessitates specific equipment and training.

Wheel bolts that aren’t correctly tightened might cause a car to vibrate violently. Take out the tire wrench from your truck and examine if any of the wheel bolts can be tightened if you feel this is the problem. Uneven rotation and vibrations can be caused by bent, chipped, or cracked rims, so be sure to inspect them for these problems as well.

3. Brakes

The friction created by the vehicle’s brakes is what stops it. An oil-filled hydraulic pump delivers brake fluid to calipers that squeeze brake pads against the disc when you apply braking pressure.

When you feel the vibrations, try to hear if there is any accompanying sound. It’s most common in the 30 to 40 mph range, when you’re trying to slow down from a high speed.

Removing and replacing brake pads or disc is a complex process that requires precise method as well as careful handling of the brake lines. Airing out the brake system can be tricky, and if done wrong, an air bubble can ruin your brakes just when you need them the most. Because testing your own brakes is quite straightforward, you can save money by doing it yourself.

4. Suspension

Car Vibrates Between 30 And 40 Mph (2)

There are numerous components in the suspension system that work together to cushion the ride from road irregularities. As a result, it is also responsible for the vehicle’s performance and stability. Vibrations of 40 mph become prevalent when one or more components fail.

Worn components

Like any other component, suspension degrades over time. When the suspension is subjected to vibrations, dampness, rust, and age, its performance is affected. Rubber and ball bearings are the weakest link in the chain of rigid metal parts. If the elimination procedure led you to suspect the suspension, see a mechanic and explain the problem, particularly the conditions in which the car begins to tremble.

Raise your automobile on a jack and try to swing the tire around to check the ball joints, wheel bearings, and tie rods for the basic examination.. You can see the entire procedure in this short video:

Worn shocks & struts

While they’re unlikely to be the source of a vibration, shocks and struts are worth checking out simply to be on the safe side. Losing control of the car may occur because a worn suspension is not able to absorb bumps and turns properly. Shocks can be easily checked by pressing down on the vehicle’s upper torso and seeing how it responds. A issue with the coils or the piston is indicated by more than one bounce.

5. Engine & Transmission

Problems with the vehicle’s powertrain can lead to vibrations at 30mph, 40mph and 60mph, but identifying them at home is the most difficult aspect. In order to eliminate all possibilities, I’ll go over each one in turn, starting with the ones that are the easiest to verify.

Clogged filters

In order for an engine to perform at its best, it needs a precise and steady supply of fuel and air. It will vibrate through the vehicle when the amount of either becomes insufficient, and the pistons won’t work in balance.

Air filters are available in a variety of shapes and sizes.

Brick-like panel filters, donut-shaped round filters, or cylindrical filters are all examples of this sort of filter. It’s easy to find yours with a simple Google search, and it’s normally located in the engine bay. For a closer look, take the clips and filter off and put them aside. The dirt may come out with a gentle tap, but since air filters are so inexpensive, it’s always best to replace them.

Finding the gasoline filter may be difficult, but Google can assist you in your search. You must remove the metal cylinder housing the gasoline filter in order to perform maintenance on it. A fuel filter service indicator may be seen in some cars, particularly those powered by diesel. Small, see-through cylinder that holds a tiny filter and retains part of the fuel that runs through system. The fuel filter and fuel level indicator need to be replaced if they are unclean.

Fuel filters can be hidden in the fuel tank and are quite difficult to access, as the fascinating guy in the accompanying video illustrates. I’ve heard so many bad stories regarding gas tank maintenance that I’m afraid to even touch it, even though I know exactly what to do. Trust me when I tell you to take your automobile to a repair since it’s not worth the risk.

Failed spark plugs

The fuel in gasoline engines needs a spark to ignite, and spark plugs provide it. The engine will have a difficult time running if more than one spark goes out. In the event of just one, the engine can still function, despite the fact that the misfiring cylinder is off-balance.

Before starting the engine to do the spark plug change, allow it to cool completely. There are two tools you’ll need: a ratcheting wrench with an extender and a spark plug socket. Remove the spark plugs and detach the ignition cables from the engine’s top. The best way to change spark plugs is in a set, and Bosch plugs are always an excellent choice, but you can also use the plugs that were already in your engine if you like.

Worn engine mounts

Because of the vibrations, if the engine were directly attached to the body, it would lead to quick part deterioration. As a result, engines make use of vibration-absorbing mounts. Engine rattling will be worse than usual if these mounts fail, and the resulting force will be enough to transmit to the passenger compartment.

Drive at a low pace on an empty road to check for problems with the engine mount. To get the car to move forward quickly, give it short, rapid bursts of gas. You’ll hear clunking and strange noises coming from the engine bay as it returns to normal. Second, you can use the brake pedal to move the center of mass forward rather than backward as in the first way.

Transmission, driveshaft & differential problems

Vibrations are to be expected with anything that has moving parts, and this is no exception. With time and use, the vibrations become noticeable even at low speeds, and this is especially true while traveling at speeds more than 40 mph. To simplify things, think of the driveshaft as a long, fast-moving pipe. It’s possible that even a minor bend will cause the car to vibrate to such an extent that it becomes unsafe to drive.

6. Interior

Door panels, dashboards, and windows gradually deform over time, resulting in an irritating vibrating noise at speeds of 30 mph or greater. Despite their insignificance, these problems are tough to resolve. There is no practical technique to restore the dashboard’s original shape when it’s exposed to the sun’s rays for long periods of time. As long as you ignore the noise, friction between parts will eventually wear off the contact and mute vibrations.


What does a bad ball joint sound like?

If a wheel is making cracking noises and the car is swaying at 40 mph, it’s likely that the ball bearings need to be replaced. Turning a bend makes a lot of creaking and cracking noises, just like tie rods. If you keep driving on a faulty ball joint, eventually it will shatter and the wheel will come off the car.

How do you know if your driveshaft is unbalanced?

If the driveshaft is unbalanced, there are a few signs to look for. Vibrations from the undercarriage are the first to appear, followed by steering issues and a trembling sensation when accelerating. Clunking, squeaking, knocking, and clicking are all examples of the sounds. It costs about $200 to rebalance a driveshaft, which includes the cost of replacing the U joint.


Finding the precise cause of vibrations at 30, 40, and 60 mph is challenging because nearly every moving part of an automobile might create them. To begin, identify the source of the vibrations and any accompanying noise, and then narrow the field of possibilities down to a small number of candidates using the process of elimination.

Check the list to see if it’s something you can manage on your own, or if you’ll need a mechanic to take care of it. It’s my sincere goal that this advice can assist you in identifying the source of vibrations in your car, allowing you to resume driving safely once more!