Power produced by your vehicle's engine, no matter how impressive its amount, is useless when it can't reach the wheels. This is why your vehicle is equipped with two axle shafts. The axle shaft, also called a halfshaft, is responsible for transmitting power from the differential to the wheels. An axle shaft is positioned on each side of the vehicle's differential, and each axle shaft is equipped with two constant-velocity (CV) joints. These joints move and revolve to accommodate an efficient torque transfer, while dissipating any vibration that might come from the transmission and the engine. The axle shaft's CV joints are packed with grease and contained inside a rubber boot; should this boot be damaged, dirt and dust can enter the CV joints and cause damage. And you can easily tell when it's time to get a new axle shaft for your vehicle. When your vehicle's starts making clicking sounds that become more noticeable during turns, it's time to browse Carparts's catalogs for a new axle shaft.
• Transmits generated torque from the transmission and differential gears to the wheels
• Prevents transmission or engine vibrations from affecting the wheels
• Supported by heavy-duty, boot-protected bearings and joints
Axle Shaft Buyer’s Guide
An axle shaft or a halfshaft transmits the engine’s power to the wheels. It’s connected to the differential on one end, and two CV joints which, in turn, connect to the drive wheel.
The typical lifespan of a halfshaft is around 100,000 miles or more than 150,00 kilometers. However, even if an axle shaft is made to last, overloading your vehicle can cause it to break.
You can spot a faulty axle shaft if you hear strange popping or clicking noises in your car as you make a turn, decelerate, or accelerate. Leaking grease and uncomfortable vibrations also indicate a bad axle shaft.
An axle shaft replacement can cost you anywhere from $24 to $1000. The price depends on where you need the replacement axle shaft and your car’s year, make, and model. Here at CarParts.com, we can help narrow down your search with our vehicle selector tool.
A lot depends on how efficiently your car runs. Take your car’s axle shaft or halfshaft, for example. Without it, you won’t be able to steer your car properly, and your engine’s vibration will affect how the wheels turn. Axle shafts adapt well to uneven surfaces and allow a better range of motion for the wheel assembly as it makes turns.
A lot of work has been put into optimizing your car’s axle shaft. That’s because it facilitates the efficient transmission of power from your vehicle’s engine to your wheels. It’s important to equip yourself with facts about your car’s axle shaft and how to spot problems with it. If you think that your car’s axle shaft needs replacing, below are some tips that you might need.
What is an axle shaft?
An axle shaft, also known as a halfshaft, looks like a steel rod with teeth cut into the ends. It’s usually concealed inside a steel housing that runs from the differential to each of the two wheels it’s connected to. This transmits the generated torque from the transmission and differential gears to the wheels. In other words, the axle shaft helps make the wheels turn.
Unlike beam axles that connect the wheels with a single beam or shaft, axle shafts are found in pairs in each vehicle. That’s the reason why they’re called halfshafts--they each do half the job of transmitting power from the differential to the wheels. Because of its design, axle shafts allow each wheel connected to it to move independently from each other. This makes turning a lot easier and smoother.
Aside from facilitating the efficient transfer of power, axle shafts also help maintain the wheel’s proper position. By bearing the weight of the vehicle itself and its additional cargo, axle shafts also help reduce pressure on the wheels.
How does an axle shaft work?
To understand how the axle shaft works, knowing a bit about the components it’s connected to can be helpful. On one end, an axle shaft is connected to the differential. The differential is a system that takes the engine’s torque and splits it, allowing the two wheels connected by the axle shaft to move independently. The final drive assembly’s rotating motion determines whether the drive wheels would make a left or right turn.
Each axle shaft has two constant velocity joints (CV joints) connected at the ends. CV joints are packed with grease and are found inside a heavy-duty rubber “boot” that keeps them in place. These rubber boots help keep out dirt and dust from affecting the performance and integrity of the joints.
CV joints revolve to help ensure efficient torque transfer. They also dampen the vibration that may come from the transmission and the engine. Basically, CV joints work with axle shafts to provide shock absorption and stability as your vehicle goes over bumps and/or potholes on the ground.
What causes damage to the axle shaft?
The typical lifespan of a halfshaft is around 100,000 miles. However, even if an axle shaft is made to last, overloading your vehicle can cause it to break. A bad axle shaft can affect a car’s performance greatly. That’s because If it gets damaged, you won’t be able to steer your car well. You’ll also be inconvenienced by your car’s excessive shaking because nothing dampens your engine’s vibrations anymore.
A damaged axle shaft can affect the components that connect to it as well. The rubber boot that houses the CV joint is usually the most affected if the axle shaft malfunctions. While it’s made of tough materials, it can rip and leak the grease inside. The usual culprits for rubber boot deterioration would be age, extreme temperatures, and road hazards.
Damage to the rubber boot causes the CV joint to fail as well. Once it does, you’ll end up with only one half-shaft instead of two. That is if the other axle shaft hasn’t been affected already.
How to spot a bad axle shaft
Spotting the damage before your axle shaft fails on you should save you the stress and inconvenience. Also, it ensures your comfort and safety on the road. There are several signs you can look out for to know if you need an axle shaft repair.
The first sign is hearing unusual clicking sounds when you turn your vehicle. Some may describe the sound as a popping noise, but when you hear it, you’ll know. This popping noise indicates that your CV joint might already be worn or damaged. You can try to place your vehicle in reverse and drive in a circle to verify the issue. If the clicking and popping noises get louder, then you’ll need a new replacement axle shaft or CV joint.
You also have to look for other unusual sounds. If your vehicle clunks when accelerating or decelerating, it can also confirm a bad inner CV joint. In addition, humming or growling noises indicate that your inner or outer CV joint might need more lubrication.
Another symptom of a bad axle shaft is feeling an uncomfortable vibration while driving. There are a lot of factors that can cause excessive vibrations in your car as you drive. To know if it’s because of a bad axle shaft or CV joint, these vibrations should be accompanied by unusual tire wobbling and difficulty steering. The said vibrations are more noticeable when you accelerate, decelerate, or make a turn.
Leaking grease is also an indicator of a faulty axle boot. If you find grease leaking into the inside of your tire, the boot may have been damaged. It doesn’t necessarily mean that the axle shaft has been damaged, but you’ll want to have it checked to avoid damaging your CV joint or axle shaft further.
How much does a replacement axle shaft cost?
Opting for a DIY solution can cut your axle shaft replacement cost by a lot. All you need is a simple guide and the correct axle shaft replacement for your vehicle.
An axle shaft replacement can cost you $24 to $1000. This largely depends on the location (front, rear, passenger or driver’s side) of the axle shaft you want to replace and your vehicle’s year, make, and model.
CarParts.com has tools to help you look for durable and quality OE replacement axle shafts. Just type in your vehicle’s correct year, make, and model into the vehicle selector to make sure you get the right one.
A General Guide to Installing an Axle Shaft
An axle shaft makes steering your vehicle possible. Its rotating motion from the final drive assembly is translated to the drive wheels to interpret as a left or right turn. Below are instructions to teach you how to install an axle shaft. Note that the steps may vary minimally from car to car-this instruction guide, however, will give you the general idea.
Required skill level: Intermediate
Needed tools and materials
- Car jack and jack stands
- Socket set
- Tire wrench
- Pneumatic drill
Jack up the car to give you enough elbow room while doing the project. Securing it with jack stands is the best way to go. After doing so, remove the hubcap and loosen the axle shaft nut using pliers. It is usually located at the very center of the wheel.
Removing the adjacent parts
Remove the wheel after the axle shaft nut is loosened. Remove the brake calipers as well by releasing the bolts that connect it to the rotor. After unscrewing the bolts, the caliper can be easily pulled off and rotated away from the rotor. Pull off the rotor afterwards until you see two or three bolts holding the hub in place. Remove these as well.
Using the high-powered tool
The hub will come off after you unscrewed the bolts that hold it in place-this will give you access to the axle nut. Remove this by drilling it in high torque using a pneumatic drill. Take a visual of the dust shield after the axle nut is removed; remember the way it is facing to avoid reinstalling it the wrong way. Remove this after inspection.
Out with the old, in with the new
The axle shaft will stick out after the dust shield is removed. Remove it using your hands. Maintain a slow and protective pace as you may unwittingly rearrange the delicate components around it. Insert the new axle shaft unit the same way as you went when you took the previous one out.
Putting everything back
Retrace your steps back to the beginning when restoring the adjacent components. If you followed the first steps, it should not cause you any problems when you place the parts back to their respective places.
Smart Shopping for an Axle Shaft
When it comes to parts that provide support for your automobile, you can't leave finding the right one to chance. With the potential to send your chassis crashing painfully to the ground, a little thought is needed. Luckily, we've put together this simple guide to give you an informed choice.
One-piece or two?
As the name indicates, one-piece axles are hewn from a single huge chunk of steel. This was the norm, back in the earliest days of the automobile. As production philosophies started to shift towards a more economy-centric mindset, they started coming out with the easier to form two-piece variety.
To answer the question for yourself, you need to figure out what matters more to you: durability or affordability. One-piece axle shafts will last you a long time but cost a good $20 dollars more. Two-piece axle shafts-by comparison-are much more affordable but are not quite as durable.
What's in a one-piece?
Apart from the overall build-quality of a one-piece axle shaft, you also should take into consideration the kind of bearings that they come with. You can check this easily on the box or catalog entry. In general, you will want to get tapered bearings over roller bearings, as the former have greater longevity.
And the two-piece?
Avoid friction-welded shafts like the plague-the process that makes them results in a significantly weaker axle shaft overall. If you have to go for a two-piece shaft to save a few bucks, invest in the more durable forged axles. These start off as solid rods that are pounded into shape and are sturdier.
The final word
Don't be cheap when it comes to axles. Go for the premium one-piece. Engineering studies from the Afyon Kocatepe University have shown that the two-piece axle shaft is far too vulnerable to fatigue fracturing. You might save a quick buck on them and are good temporary replacements, but they will cause more long-term grief than anything else!
So You Want to Change Your Axle Shaft
Made to resist the constantly torsion of your ride's drive train and support a good chunk of its weight, an axle shaft is the thickest bit of steel on any chassis. Installing a new one in your automobile might seem like a daunting task at first, but with this handy guide, you'll be up and driving in no time! As a matter of fact, you can do this task within 30 minutes to an hour.
Difficulty level: Moderate
Stuff you'll need:
- New axle shaft
- Your vehicle's owner's manual
- A jack
- Jack stands
- Ratchet and socket set
- Tire wrench
- High-powered drill
Step 1: Disengage your vehicle's battery to prevent nasty electrical shocks! Wait a good half hour before you begin.
Step 2: Take off the hubcap or center cap on the wheel of the side you want to install a new axle shaft in.
Step 3: Carefully loosen the axle shaft nut which is located in the center of the wheel.
*NOTE* With some vehicles, there's a cap that needs to be detached first. Use the pliers to remove the cotter pin holding it down.
Step 4: Elevate your ride with the jack and secure it with jack stands. Important: Make absolutely sure that this is secured before you begin tinkering under there.
Step 5: Remove the wheel.
Step 6: Take off the attached break calipers by taking off the bolts that root them to the rotor.
Step 7: Carefully pull off the calipers using a rotating motion.
Step 8: Take the rotor out.
Step 9: Using the ratchet, take off the bolts holding the hub where it is then ease the hub off.
Step 10: Remove the axle nut.
*NOTE* This step might require the use of the drill. Try a little tug and twist test on the nut-it just might save you time if you can just take it out normally.
Step 11: Make a note of the exact appearance and facing of the dust shield underneath the hub then remove that as well.
Step 12: Insert the new axle shaft very slowly.
Step 13: Re-attach the dust shield, axle nut (and cotter pin, if present), and the hub-in that order, making sure to tighten all attachments.
Step 14: Replace the wheel and secure it in place.
Step 15: Carefully lower the wheel to the ground.
*NOTE* Peek under the car and test the installation by applying weight on the area.
Step 16: Re-affix your hubcap or center cap.
Step 17: Re-engage your battery and drive off into the sunset.
- Always play things safe: wear goggles, gloves, and keep your shoes decidedly closed-toed.
- Keep the owner's manual close by: it's your sure guide and the final word in any discrepancies with our guide.