What are Leaking Axle Seal Symptoms? | How to Replace the Axle Seal?

The axle seal connects the axle to the transmission and prevents the transmission fluid from the leak. Depending on the size of the leak, it may be okay to drive with a leaking axle seal, but you probably won’t get very far. This article mainly explains the symptoms, causes, and repair costs of the axle seal leak.

What is a Rear Axle Seal?

A rear axle seal is a seal located between the rear axle and the differential of a vehicle. The rear axle seal is responsible for sealing the differential gear oil inside the differential housing.

axle seal

Causes of a Leaking Axle Seal

The axle seal goes bad or leaks due to one of the below-given causes:  

  1. The most common cause of a leaking axle seal is improper axle installation or removal.
  2. The axle seal can wear out over time, which can cause it to leak. Over time, the seal starts to break down, allowing oil to leak. This can happen if you don’t regularly maintain your vehicle or if you drive it hard.
  3. Another reason the rear axle seal can go bad is an accident. If you hit something hard enough, it can cause the seal to break and allow oil to leak out. This is why it’s always important to get your vehicle checked out after an accident, even if it doesn’t seem like there’s any damage.

Symptoms of Rear Axle Seal Leak

When the rear axle seals leak in vehicles with solid rear axle housings, it leaks gear oil from the rear differential, which leaks out into the rear brake area and fouls your brake shoes.
When the shoes get impregnated with gear oil, they can’t be effectively cleaned, so it’s best to replace the shoes.

Symptoms of Real Axle Seal Leak

Following are the most common symptoms of a leaking axle seal:

  1. Oil drops below your vehicle: One of the more common signs the axle seal is leaking is oil below your vehicle after it has been parked. Your driveway is one of the spaces you will notice the oil leak. If you start to notice oil drops on your driveway, it could be a sign of a leaking axle seal.
  2. Transmission starts slipping as you are driving on the highway: While an oil spot on the driveway is a common sign, it does not always happen because the axle seal leaks more during highway driving. Instead, you may notice your transmission slipping at highway speeds. Since the transmission fluid drops, there is not enough fluid for brake band friction, valve operation, gear lubrication, and the torque converter. If the leaking axle seal does not get fixed soon and the transmission is slipping, you could cause permanent damage to the transmission.
  3. Low Transmission Fluid Level: One of the most common symptoms of a bad rear axle seal is if transmission fluid drops. If your transmission fluid level drops, it is probably because the rear axle seal is leaking.
  4. Clicking Noise: A clicking noise is another symptom of the axle seal leak. When the differential gears are not properly lubricated, they can start to make a clicking noise.

How To Fix a Rear Axle Seal Leak?

Follow the below-given steps to fix a leaking axle seal or to fix it:

  1. Raise your car on a jack. Place jack stands underneath the car for safety.
  2. Locate your rear axle seal. The axle seal is usually found on the differential, which is located near the back of your car.
  3. Remove the retaining clip. For this, push your axle towards the differential opening; you will notice the slop or movement of the axle. This will allow you to take a magnet and remove the axle retaining clip, shimmying it if necessary. 
  4. Once you removed the axle retaining clip, the axle is free to pull out of the housing. Before removing you will need to place your second drain container underneath the end of the axle tube. Take a couple of rags and grab the axle flange, slightly pulling the axle out. During the removal, slowly wipe the axle shaft as it comes out of the axle housing.
  5. Now remove the seal. Hook the inside of the seal with the hooked end of the seal puller and pull or push depending on your position. Make sure not to damage the surface around the seal.
  6. Now clean the area around the seal thoroughly. Any dirt or debris could prevent the new seal from sealing properly.
  7. Place the new seal in the opening. Make sure it is seated properly.
  8. Now, put the rear differential cover back on the car.
  9. Lower your car off of the jack stands.
  10. Test drive your car to see if the leak has been fixed. Once the new seal is in place, you should not have any more leaks.

How much does it cost to fix a leaking axle seal?

The replacement or repair cost of an axle seal leak varies according to the labor cost, the vehicle type, and the type of brand. The average replacement cost of the axle shaft seal is from $240 to $300. In this cost, the costs of the parts are from $35 to $60, while the labor cost is from $205 to $240.

FAQ Section

What is the function of the axle seal?

In a car, an axle seal is a part that seals the connection of a CV axle (driveshaft) to the transmission or rear differential. The job of an axle seal is to keep the transmission fluid or differential oil from leaking out.

Can I drive with a leaking Axle Seal?

The severity of the leak affects how safe it is to drive with a leaking axle seal. If there is significant fluid loss, so much that it affects the transmission, the vehicle should not be driven.

If the leak is small and you can’t make it to an appointment for a few days, it is okay to drive your vehicle as long as you keep the transmission fluid full. Do not push it too far, though, as ruining your transmission is an expensive repair.

What is the average service life of a rear axle seal?

The average lifespan of a rear axle seal is between 50000 and 100000 miles. However, this can vary depending on the make and model of the vehicle as well as driving habits. Proper maintenance of the rear axle seals can help extend their lifespan.

How many axle seals does a car have?

All vehicles today are front-wheel drive, rear-wheel drive, or all-wheel drive. Each vehicle has an axle that provides power transfer to the wheels. Each axle is different in every way and has two to three seals on them.

How do I know if my axle seal is leaking?

A leaking axle seal generates one of the below given symptoms:

  1. Oil drops below your vehicle
  2. Transmission starts slipping as you are driving on the highway
  3. Low Transmission Fluid Level
  4. Clicking Noise

Can I drive with a leaking CV axle?

The Constant Velocity or CV axle is sealed by a boot. This boot may get damaged, and when this happens, the joint will wear out and eventually fail. If you drive a car with a damaged CV, the joint will disintegrate further, making driving impossible. You’ll not be able to control the vehicle and may get involved in an accident.

Can transmission fluid leak from the axle?

One of the most common and probably most noticeable signs of a problem with one of the vehicle’s axle shaft seals is a puddle of fluid underneath the car. When the axle shaft seal fails, oil or transmission fluid can leak from the transmission or differential.

Where are axle seals located?

An axle shaft seal can be found in a few different places: On a vehicle with a semi-float live axle, the seal is at the outer end of the axle tube. On a truck or SUV with front CV axles, the axle seal is at the inboard end of the axle, where it goes into the differential.

Can leaking axle seal affect transmission?

Depending on the design, the front axle shaft seal mounts into the axle shaft tube or the differential case and prevents the internal fluid from leaking out. If the front axle shaft seal becomes compromised, transmission fluid will leak and possibly damage the transmission or differential.

What does an axle seal leak look like?

The first symptoms include reddish-brown fluid drops behind the left front wheel, where the left front driveshaft connects to the transmission. An axle seal leaks more during highway driving, so the oil drops on the driveway may not always be present.

What is the material of an axle seal?

The material of an axle seal is typically made of metal, such as steel or aluminum. However, there are also some seals that are made of composite materials, such as fiberglass or carbon fiber. These materials are chosen for their strength, durability, and resistance to wear and tear.

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