The front wheel drive axle on Honda Fit.

Kinds of car axles used today, bad axle symptoms

In Maintenance by Steves Auto Repair and Tire

A lot of traveling happens between celebrations, fun with family, and day-to-day tasks.

Axles help keep our vehicles moving. So it’s important to make sure that they are in good shape.

Your vehicle may have a bad axle if you notice any of these problems:

  • Shaking steering wheel
  • Clicking noise
  • Noisy u-joints
  • Axle seals are leaking
  • Grease on tires

We will go into more detail later in this article. But first, let’s discuss the different kinds of car axles that can be found on vehicles nowadays.

Each vehicle is designed with different purposes and capabilities. The type of axle yours has is determined by a few different factors.

Types of car axles

The axles typically seen on automobiles today are: CV Axles, Straight Axles and Rear Axles.

Constant-Velocity Axles (CV) Axles

Constant-Velocity (CV) Axles are the first we will talk about. They feature CV joints that allow the front wheels to be equally operated by the transmission. 

A lot of cars that have front wheel drive and certain four-wheel drive ones feature CV Axles.

You may see them on vehicles with independent suspension, including the front of 4-wheel drive trucks and Subarus with all wheel drive. 

Sometimes, two kinds of axles are used. For example, CV Axles might be used on the front of a truck while Solid Axles are installed on the rear.

Straight Axles

Straight Axles are the next type we are going to discuss. Used on different suspensions, Straight Axles come with a simple design.

Years ago, these axles were pretty common among automobiles. Today, their usage is mainly limited to heavy duty trucks and the front of work vehicles. Jeeps and trucks that are lifted or used for offroading may have Straight Axles, as well.

U-joints can be found on the front of certain four wheel drive Jeeps. These parts make rotating the wheels possible.

Rear Axles

Lastly, there are Rear Axles. They have axle shafts that the differential links. 

Rear Axles come in varying designs – semi-floating, which can be seen on cars, light trucks and SUVs; and full-floating axles, which tend to be installed on heavy duty and certain mid-size trucks.

In the semi-floating axle design, the wheel and flange are attached by the axle. Meanwhile, full-floating axles rest on bearings and are held in by a retainer on the outside.

How to tell when axles are going bad

Earlier, we mentioned some bad axle symptoms. We would like to provide a deeper explanation about these different indicators.

Shaking steering wheel

A shaking steering wheel can be the result of the CV joint on a front wheel drive axle binding up due to lack of lubrication or wearing out. U-joints that go from the axles to the spindles on older jeeps with a straight axle on the front may bind up, as well.

Clicking noise

You could also hear a “click” while turning or accelerating. The CV joint might start making a clicking noise when it’s worn out from daily use. If the CV boot is broken or torn, water can get in, preventing the grease from working properly. If it’s really torn, sand and dirt start to collect and act as sandpaper. This causes it to wear out more quickly. You get the clicking noise when making a turn because it’s starting to bind up.

Noisy u-joints

Clicking isn’t the only sound you might hear. For vehicles that have straight axles, a squeaking sound can be coming from the u-joints.

Axle seals are leaking

On a front wheel drive car, axle seals would be in the transmission. If you have a bad axle that’s causing a vibration or bouncing up and down more than it should, that could make the seal go bad faster.

Grease on tires

When an axle boot tears, grease leaks out and can sometimes land on the tire. This is why it’s good to go to an auto repair shop that looks over different components of the vehicle to catch things like this. It may not be something you see just by looking at it at ground level.

Ways you can take care of axles

As with other parts of a car, maintenance allows the car axles and components associated with them to last.

This includes getting the CV Axle boots and the vent cap of Solid Axles inspected regularly.

U-joints should be checked and greased (when necessary), as well.

It’s also important that those who drive vehicles with straight axles ensure that auto repair shops and professionals use the correct kind of differential fluid when servicing them.

If you believe that there is something wrong with your car axles or you find out they’re going bad, don’t avoid replacing them.

The problem can worsen the longer it goes without being addressed. Plus, the consequences could extend to other areas of the car.

Steve’s Auto Repair & Tire is an authorized Goodyear tire dealer located in Woodbridge, Virginia. Automotive repair services are performed on all makes and models, including BMW and Mercedes. Services include oil changes, brakes, alignments, inspections, and computer engine diagnostics.