Complete Guide: How To Troubleshoot Excavator Final Drives (2022)


The main job of the Excavator’s final drive is to transfer engine power to the track and provide propulsion. It helps to increase traction force and optimize the power of the Excavator.

Excavator Final Drive

The benefit of Excavator final drive is that it houses all the gearbox components and motor inside protective housing, this ensure a long life and better working efficiency of your excavator.

With excavator final drive you can take your excavator in any area you want as it enable your excavator to move on steep, flat, uneven grounds.

The final drive of an excavator houses its gearbox and hydraulic motor.


Why Troubleshooting Excavator Final Drive Matters?

Troubleshooting the excavator’s final drive helps identify the problems causing failures in the system. Such losses can lead to machine damage, unsafe working conditions for operators, and a huge increase in repair, maintenance, and replacement costs.

Troubleshooting excavator final drive

It’s imperative to troubleshoot the excavator’s final drive. For example, you don’t want to overwork your engine unnecessarily. This will also help ensure that the engine operates efficiently and helps in its proper functioning.


When you Troubleshoot your excavator final drive periodically then it ensures that your excavator remains good condition and keep maintenance costs lower. A little troubleshooting goes a long way in increasing the life of your excavator’s final drive system.


Troubleshooting Your Excavator Final Drive

Several issues may lead to the excavator’s final drive loss of power, noise, leaks, overheating, and vibrations. Let’s find out the major problems and how you can solve them.


1.    Noise

In a broad sense, noise is a sound that is unwanted or considered unpleasant. Noise is one of the most critical aspects to consider in an excavator’s final drive. When you experience this issue, do not avoid it. Here are some reasons for the noise in your Excavator’s last industry.

Insufficient Lubrication

Insufficent lubrication


Noise in an excavator’s final drive could be caused by using outdated gear oil. Excavator final drives are fueled by oil, leading to engine failure if oil levels are not monitored adequately. Oil replacement or level checking is always necessary.


Worn-out Bearings


Bearing failure


Worn-out bearing is a common problem in the excavator’s final drive. When the bearing wears out, it will make a lot of noise, affecting the service life of other parts such as the main shaft, reducer, and power take-off components and even causing failure of these parts. If you maintain the oil level in your Excavator’s final drive, worn-out bearings are causing the noise. Practice timely replacement to avoid severe issues.


Worn-out Gears

Worn out gears


The final drive gears spin with the tracks and constantly transfer torque. These gears can wear out with age and use like any other mechanical component. Worn-out equipment will have excessive clearance between its mating parts, resulting in a loss of efficiency and excessive noise. The only solution is to replace the worn-out gears in time.


Faulty Charge Pump


Charge Pump Failure


A final drive motor might make various sounds, such as a low-pitched growl when the speed is slow, and then it will progress to a high-pitched whine. These issues are mainly due to because charge pump. The recommended solution is to replace the charge pump.


2.    Vibrations

Vibration is a random, irregular movement of small amplitude and short period. It can be felt as a whole-body vibration or as a more localized vibration – for example, in a final drive.

You can experience a vibration at lower amplitude and higher amplitude. The vibrations with higher amplitude possess more damage to your excavator final drive internal components. You must troubleshoot your excavator final drive from time to time to avoid them. This will make you prevent your excavator from severe damage.

Some primary sources of vibrations in the excavator’s final drive are as follows:



Loose Fitted Sprocket

Loose Fitted Sprocket, also called Out of Alignment Sprocket, is a severe mechanical problem in the final drives of an Excavator as it leads to vibration, stress, and premature failures.

 Loose fitted sprocket


Loose Fitted Sprocket may cause transmission failure due to mechanical overloads and failure of bearings, leading to significant damage costing thousands of dollars. Either Tight the loose sprocket or replace it to enjoy maximum efficiency.


Final Drive Shuddering

Final drive shuddering

Final Drive Shuddering is the unwanted, irregular movement of the track under load. The term shuddering represents the damage extent in your excavator final drive. If there is more shuddering then you may expect more damage. If it is not due to a loose sprocket, it is because of poor maintenance and misuse. In this case, the only solution is to replace the whole drive.


3.    Too Much Heat

The overheating of the excavator’s final drive refers to the friction and heat generated between the components, such as bearings, and the gear is too large. The temperature sometimes exceeds its limit, resulting in a large amount of heat generated. Some of the main reasons given below for your reference:


Low Gear Oil

Gear Oil is used to lubricate and cool gears, bearings, and bushings in an excavator’s final drive. The oil circulates through the system, keeping all moving parts lubricated, reducing friction, and increasing efficiency.


If your gear oil level is low, your engine will overheat or break down from excessive wear because, in this case, the heat transfer is carried out from final drive components.


High-Temperature Hydraulic Fluid

If there is no issue with the oil level in gears, the overheating might be due to overheated hydraulic fluid. This may be due to the cooling system of hydraulic fluid not exchanging the heat of components properly. Measure the hydraulic fluid temperature entering the excavator’s final drive periodically. If needed, replace the cooling system for maximum machine output.


If the oil level and hydraulic fluid temperature are not causing the issue, it may be the brake. Eliminate potential causes such as stuck calipers or worn brakes. If they’re not the problem, be sure first to check the brakes to ensure they are releasing completely. In case of the brake is not removed altogether, they result in excess friction.

The possible cause of the break not functioning is as follows:

  • Residual Pressure in Circuit



Residual Pressure in Circuit is a problem excavators face using the final hydraulic drive.

Residual pressure in the circuit describes that pressure is not transferring completely from the circuit to the brakes. Some pressure might dissipate in the lines or in the circuit This will prevent them from functioning.


Residual pressure can cause brake failure if a failure occurs in the hydraulic circuit causing all hydraulic pressure to be lost. Thus, less force is generated on the brake’s friction surface. Your ability to stop or slow down your machine is significantly reduced if not eliminated altogether or permanently damaged.

  • Worn Brake Discs

Worn Brake Discs


Worn Brake Discs are among the most common issues in final excavator drives. The following are some of the causes of worn brake discs in excavators:

  1. Excessive usage beyond the permissible limits,
  2. Frequent stop-and-go traffic,
  3. Unreasonable speed while driving and
  4. Unsuitable driving patterns such as hard braking at low speeds can also cause this failure.


Over time, the disc wears out as it is exposed to a great deal of heat and pressure, which, combined with high rotational speed, causes the material to wear out, reducing its thickness and creating grooves on its surface.

That will lead to the failure of brake functioning, which leads to heavy damage to the machinery or may result in an accident. Replace the disc if you notice any signs.

  • Broken Motor Shaft

Broken Motor Shaft



Broken Motor Shaft in excavator final drives is a common problem among most underground mining excavators. It can lead to failure of brake functioning or breakage of the gearbox housing or the impact gears that may result in an accident. It can also lead to other losses such as broken bearings, shafts, and seals.


If it fails to rotate correctly, the direction of rotation of the pinion turns reverse and causes severe damage to other parts like the gearbox and axle. The consequence: Excavator stops working. So, to get maximum working period and sound output, it should be appropriately maintained by performing regular checkups.


5.    Leakage

If a leak happens in your final drive, it can present many problems. Fluid can seep out of the system and cause drips to be left everywhere. It could also lead to places where other dirt & moisture could accumulate. If you think it might be something like this, try & narrow down the problem areas.



Hydraulic Fluid

Hydraulic fluid is extremely thin, especially in gear oil, so it can quickly leak through hose-related faults. This may also be caused by rotten seals that have blown out. Explosion and fire risks are possible risks associated with blown internal seals because they might over-pressurize the fluid, which causes an exothermic reaction.


Gear Oil

If your machine is equipped with a spinning sprocket, the oil will leak out of the sprocket if you have an internal combustion engine and it’s not sealing properly. If it’s dripping onto the track, then the cause is likely a worn down or incorrectly torqued thread in the transmission sleeve. Detect the passage from it is leaking and replace the seals in time to avoid this issue.

Another possible leaking issue is to refill the oil more often than usual. This will also cause oil leakage.

Causes of Leakage

There are two main reasons which lead to leakage, and they are listed below for your reference:

  • Distorted Gearbox Cover

Gearbox Cover distorted in Final Drive is a critical issue, as it can affect the oil supply to the gears, so you should check it each time before starting up your Excavator. The gearbox cover keeps dirt out of the lubricant and limits the amount of oil lost while operating on site. The most common causes of distorted gearbox covers are:

  • Machine overload
  • When the machine has just been idle for long periods
  • When operating in areas that are cold or wet.


What do you need to do in this case? The solution is that you will need to replace the case cover and O-ring and have it machined down on any distortions it may have.

  • Pressure Build-Up in Gearbox


Pressure build-up in the gearbox can cause catastrophic failure of transmission. The pressure build-up may be generated due to:

  • Excessive Load,
  • Oversize Gears,
  • Incorrect Lubrication
  • Oil leakage
  • Component wear or rust in the lines,

The immediate consequence is the breakage of components like gears, bearings, etc., followed by the destruction of the gearbox.

6.    Power Loss

You may experience this issue in either single or dual final drive motors.


Determine if the Loss of Power is On One side or Both sides?

Power loss occurs when one or both sides of the final drive are damaged or misaligned. This renders the machine useless, so it must be repaired immediately. Power loss is defined as any drop in the torque or pulling power of a component’s engine. Motor failure, mechanical breakdown, gearbox failure, and other issues can cause power loss—in either single or dual components of the machine’s final drive. With this problem, you will experience the following points also:


  • You cannot carry the load on your final drive
  • You cannot move it either forward or backward
  • You will experience the drift on the side where the final drive experiences power loss
  • Your Excavator cannot make it up on steep slopes


The only solution is to replace the whole final drive to keep up with your excavation operations.

7.    Lost Turning Ability

The final drive may not turn. You may experience this situation. In this case, the motor works, but the gearbox may fail to operate the reasons are as follows:

Broken Sun Gear

broken sun gear

Broken Sun Gear is a phenomenon that occurs in final excavator drives. It is caused by excessive transmitting power, causing high temperature and impact loads on the sun gear and pinion shaft.


As a result, the metal component of the sun gear is cracked, which reduces the clamping force of the bearing and leads to zero turning of the final drive. In addition, as long as the broken sun gear remains, it can cause repeated damage to other components. The solution to this issue is to replace the sun gear quickly and effectively.


Motor Service Life Completed

Motor Service Life Completed or motor longevity is an essential factor in the life of a construction excavator. Motor service life depends on several factors, including operational considerations and maintenance practices. When we say that the service life is completed, drivers cannot continue functioning. This may be one reason for the loss in turning ability of your Excavator’s final drive.

Final Words: Excavator Final Drive Troubleshooting

The final drive is one of the most complicated and essential parts of a wheel loader. It has a lot to do with your excavator’s performance, power, and overall capabilities. The biggest issue with final excavator drives is not knowing when something might go wrong.

You can apply the useful information mentioned in this guide to determine the issues you are experiencing while in field. It also helps you to keep your excavator’s final drive maintained.

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