The axle seal links the axle to the gearbox and stops the transmission oil from the leak. According to the size of the leak, a leaking oil seal may work, but it probably can’t get very far. This article primarily covers the symptoms, causes, and repair costs of the axle seal leak.
What is a Rear Axle Seal?
The rear axle seal is the seal mounted between the differential and the rear axle of the car. This seal is used to seal the differential gear oil in the differential housing.
Symptoms of a Rear Axle Seal Leak
A leaking rear axle seal on a vehicle with a rigid rear axle housing can allow gear oil to leak out from the rear differential and go into the rear brake area, contaminating the brake shoes.
If your vehicle’s shoes are soiled with gear oil, they can no longer clean themselves effectively, so replacement is recommended.
A leaking rear axle seal generates one of the below-given symptoms:
1) Oil drops under your Car
The oil under your car after it has been parked is one of the most common symptoms of a leaking axle seal. The driveway is an area where you can easily observe the leakage of oil. Observing oil drips on the driveway could be a sign of a leaking axle seal.
2) Clicking Noise
Clicking is another symptom of a leaking axle seal. If your differential gears are not oiled efficiently, they will produce a clicking noise. This clicking noise is produced due to the metal-to-metal contact of the gears.
3) Slipping Transmission
Oil stains on the driveway are a common symptom, but they don’t always happen because axle seals leak more when driving on the freeway. Conversely, you may observe that the gearbox starts slipping at high speed.
Due to the low transmission oil level, there is not sufficient oil for the torque converter, transmission lubrication, valve operation, and brake band friction. If you do not immediately fix your leaking axle seal, then your transmission will continuously slip, which may permanently damage the transmission.
4) Low Transmission Fluid Level
The low transmission fluid level is one of the most common symptoms of a damaged rear axle seal. If the transmission oil level is dropping continuously, it may be due to a leaking rear axle seal.
Read More: Symptoms and Causes of a bad CV Axle
Causes of a Leaking Axle Seal
The axle seal goes bad or leaks due to one of the below-given causes:
- Wear and Tear: With the passage of time, your axle seal may wear out. When the seal wears out, it leads to oil leakage. Your seals may crack if you don’t regularly maintain your vehicle or if you drive it very hard.
- Poor Installation: Improper shaft removal or installation is one of the most common causes of axle seal leaks.
- Physical Damage: Another cause of a damaged rear axle seal is an accident. Hitting it hard will rupture the seal and cause an oil leak. Therefore, you must check your vehicle after an accident, even if it doesn’t appear to be damaged.
Read More: Causes and Symptoms of Bad Wheel Bearings
How To Replace a Rear Axle Seal Leak?
Follow the below-given steps to fix or replace a leaking axle seal:
- Use a jack to lift the vehicle. Place a jack under the vehicle for safety.
- Find the rear axle seal. The axle seal is usually located in the differential near the rear of the vehicle.
- Now eliminate the retaining clip. To do this, slide the shaft in the direction of the differential opening. You will observe that the axle tilts or moves. This allows you to grab the magnets and eliminate the retaining clip from the shaft, which you can adjust as needed.
- As you remove the axle retaining clip, the axle will slide freely out of the casing. A second drain pan should be placed under the end of the axle tube before removing it. Use a rag, grasp the axle flange, and gently pull the axle out. It will come out of the axle housing when disassembling, so clean it carefully.
- Now remove the seal. Hook the inner side of the seal onto the hooked end of the seal puller and push or pull according to your position. Avoid damaging the surface around the seal.
- Thoroughly clean around the seal. Contamination can prevent the new gasket from sealing efficiently.
- Install the new gasket in the opening. Your seal must be installed properly.
- Reinstall the rear differential housing on the vehicle.
- Lower the vehicle off the jack stands.
- Test drive the car to see if the leak has been fixed. Once the new gasket is in place, there should be no more leaks.
Axle Seal Replacement Cost
The repair or replacement cost of a leaking axle seal depends on the labor cost, the vehicle type, and the type of brand. The average replacement cost of the axle seal is between $230 and $310. In this cost, the parts costs are from $30 to $70, while the labor costs are from $200 to $240.
| Labor Cost | $200 to $240 |
| Parts Cost | $30 to $70 |
| Total Cost | $230 to $310 |
Axle Seal Location
The location of the axle seal varies according to the vehicle model. In vehicles with semi-floating drive axles, the seal is usually located on the outer edge of the axle tube. On a truck or SUV with a front CV axle, the seal is located at the inboard end of the axle and merges into the differential.
What is the material used for the axle seal?
The axle seals are usually made of metal, such as aluminum or steel. But there are also seals made of composite materials like carbon fiber or glass fiber. These materials have been chosen due to their abrasion resistance, durability, and strength.
Frequently Asked Questions
What is the function of the axle seals?
In the vehicles, axle seals are used to seal the connection between the CV axle (driveshaft) and the transmission or rear axle differential. The main function of the axle seal is to prevent leakage of differential oil or transmission oil.
How do I know if my axle seal is leaking?
A bad axle seal generates one of the below-given symptoms:
- Clicking Noise
- Oil drops under your Car
- Low Transmission Fluid Level
- When driving on the highway, the transmission begins to slip
How many axle seals does a vehicle have?
The latest vehicles are all-wheel drive, rear-wheel drive, or front-wheel drive. Every car contains an axle that transmits power to the wheels. Each axle is different in every way and contains two or three seals.
What is the average life of a rear axle seal?
Rear axle seal life expectancy is 49,000 to 100,000 miles. But this lifespan may change according to the seal material, car driving method, and model of your car. Proper rear axle seal maintenance will help extend its life.
Can you drive with a leaking Axle Seal?
The severity of the leakage can affect the operational reliability of leaking shaft seals. Do not drive your vehicle if a large fluid loss is affecting the transmission. If the leak is small and you don’t want to repair it for just a couple of days, have the transmission oil topped up, and you’re good to go. But don’t overdo it because this leak can permanently damage the transmission and the transmission replacement is very expensive.
Can leaking axle seal affect transmission?
According to vehicle design, the front axle seal is attached to the differential case or axle tube to stop inner oil leaks. A damaged front axle shaft seal can leak differential oil and may damage the transmission.
Can I drive with a leaking CV axle?
A boot is used to seal the Constant Velocity or CV axle. These boots can become damaged, and when this happens, the joints wear out and ultimately fail. Driving with a damaged CV axle causes additional damage to the joints and makes driving terrible. You could lose control of your car, which may lead to a car accident.
Can transmission fluid leak from the axle?
One of the most common symptoms of an issue with one of your car’s axle seals is a pool of oil under your car. A bad axle seal can cause transmission fluid to leak out of the transmission.
What does an axle seal leak look like?
Early symptoms included red-brown fluid droplets behind the left front wheel, where the left front driveshaft attaches to the gearbox. The driveway does not always leak oil due to increased axle seal leakage while driving on the freeway.
