Importance of Gear Oil In Final Drive Maintenance

The final drive is the most important link between the engine and wheels. Gear oil lubricates this link to ensure smooth power transmission from the engine to the wheels. If the gear oil fails, it can cause problems in the final drive.

The main reason behind final drive failure is zero or bad maintenance. Therefore, this post aims to reflect the importance of gear oil while maintaining your final drive. Why should you include this maintenance measure in your maintenance schedule? Sounds great? Read on to learn more!


Gear oil is a viscous liquid that consists of polymers and minerals. The function of the gear oil is to prevent excessive wear and tear of the gears. The gear oil in the excavator drive removes heat from the machine’s internal components.

People most often ignore the final drive while using their excavators. Instead, they provide torque and power to excavator wheels.


This power makes your entire excavator move from one location to another location. It also assists in driving over terrains. Due to any reason, if your final drive stops working, it will contribute to downtime on the job site.

Suppose you continue using your final drive by ignoring the maintenance measures. Then this will result in severe damage to your excavator’s final drive. Most often, this is due to not inspecting the gear oil in your final drive.

Importance of Gear Oil

The final drive contains multiple gears arrangement known as planetary gears. They double the torque they receive from hydraulic motors as the gear assembly does not contain any hydraulic fluid. This is the reason why you need to put inside the gear oil. There are two main functions of gear oil which are as follows:

  • Using gear oil, you can protect the key surfaces of your planetary gears, sun gear, or bearings.
  • It will also play an important role in eliminating the heat which builds up due to continuous motion.

This is the main reason why you should maintain your final drive. You can do this by observing your gear oil’s oil level and age.

Consequences of Low Gear Oil

Low oil level in your gears severely harms your final drive. You cannot protect your bearings, gears, or shafts, increasing the friction between various components.

Friction refers to the certain force that resists or slows down the motion of an object or surface. This can cause you to use energy inefficiently. Friction occurs when two surfaces contact one another.

If they make contact while moving, it results in heat buildup. This happens within the final drive assembly. The friction also results in abrasive contaminants formation. This will lead to more damage. This is why you need to inspect the level of gear oil periodically.

If you have low-gear oil, you can add more oil or replace it with new oil. If the low oil sustains for a considerable time, you will observe a seal leakage soon.

Seal Leakage

The damage or leaking seal is unacceptable. You ignore the oil level in your final drive or keep it low for enough time. This will lead to sealing leakage. Seal leakage is severe because of the following reasons:

  • It leads to gear oil escape from your final drive resulting in further reduction in oil levels
  • When you have a leaking seal in the final drive and working in the swamp area. It causes dirt, sand, debris, etc., into your final drive.

These damages can render your shaft, gear teeth, and bearing failure. Thus, making your final drive completely useless.

Gear Oil Overage

The age of gear oil is a critical thing to note. When the age of gear oil exceeds its limit, you will experience the following things:

1.    Change in Color

If the oil looks a little darker than you would like, it is time to change your engine oil. This indicates that the oil is bleeding off its contaminants and impurities.

If a gear oil change is due, you can use the color chart on the side of your gearbox to check if it is time for a new oil change. This will tell you when your gearbox needs a new supply of oil.

2.    Change in Viscosity

The viscosity of gear oil is one of the indicators to detect the overage of gear lubricant. The change in viscosity you can measure by using a viscometer.

A gradual increase in the viscosity indicates the overage of oil, while a sudden increase in viscosity indicates contamination. Engine running at higher speeds or elevated temperatures will accelerate this viscosity change.

3.    Antioxidants/ Molecules Breakdown

When gearing oils break down, the antioxidants (molecules) in the oil are broken down by oxidation.

The particles that make up the antioxidant coatings help protect the parts of a part and keep them from rusting. With this type of breakdown, you experience an increase in oil consumption and final drive gear wear over time.

4.    Smelly Sludge

Sludge refers to the thick, soft, mud-like structure. Sludge is the type of oil formation that is due to excessive contaminants and worn-out pieces of material components.

It largely occurs due to poor lubrication conditions. As time passes, the smell begins to develop in oil. All these signs indicate you must need to change your gear oil within the final drive.


Per our recommendation, check your gear oil level once in 100 operational hours. For changing, we recommend you to change your gear oil once a year. Do not underestimate lubrication. This will increase the life of your final drive and get you a larger ROI.

We have discussed everything you need to know regarding the importance of gear oil and needs. Suppose you have any suggestions or questions regarding gear oil, comment below. We would love to assist you.

Your final drive gear oil must be in good condition so that it will not affect the performance of other parts. But it’s undeniable that your final drive gear oil is expensive, and its replacement requirement is regular.

Xugong can help you replace your vehicle’s high-quality and high-performance lubricant. It will also cut your labor cost in half, saving much of your budget.

Change the old, inferior, low-quality lubricant for Xugong Final Drive Gear Oil to protect your car!


Scroll to Top

Get a Quick Quote!


    Get a Quick Quote!