How to Pull the Front Axle Stub on a CAT 70 Scraper: A Step-by-Step Guide

[MikePhua]

Introduction: The Importance of the Front Axle Stub in Scrapers
The front axle stub of a CAT 70 scraper is an essential part of the machine’s drive system. It connects the front wheels to the chassis and plays a critical role in distributing power from the drivetrain to the wheels. Over time, this component may wear out or become damaged, requiring repair or replacement. When working on a CAT 70 scraper, it's important to know how to properly remove and replace the front axle stub.
In this article, we will discuss the common procedures and best practices for pulling the front axle stub on a CAT 70 scraper. We’ll also highlight the importance of proper maintenance and preventive care for the machine’s performance.
Understanding the Role of the Front Axle Stub
The front axle stub is a crucial part of the scraper’s front axle assembly. It is responsible for transferring rotational motion from the axle to the front wheels. Given its role, the axle stub must withstand significant stresses, especially during high-load operations such as hauling or earth-moving. Any damage to the stub can cause improper alignment, uneven wear on the tires, and potential breakdowns if not addressed quickly.
Regular maintenance and inspections of the axle stub are essential to ensure the longevity and efficiency of the scraper.
Why You May Need to Pull the Front Axle Stub
Several reasons may necessitate the removal of the front axle stub:

1. Damage to the Axle Stub
   If the axle stub has been damaged due to a heavy impact or general wear and tear, it may need to be replaced. This damage could manifest in bent or broken parts that affect the scraper’s performance.
   
2. Wear and Tear on Bearings
   Over time, the bearings in the axle stub can wear out, leading to increased friction, noise, and overheating. Replacing the axle stub may be necessary to keep the scraper functioning optimally.
   
3. Preventive Maintenance
   In some cases, preventive maintenance or scheduled replacements may prompt the removal of the axle stub. Regular inspection and maintenance of the front axle stub can help avoid unexpected breakdowns in the future.
   
4. Upgrades or Modifications
   If you're upgrading or modifying your CAT 70 scraper to improve its performance, the front axle stub may need to be removed to facilitate the installation of new components.
   

Steps to Remove the Front Axle Stub
Here’s a detailed breakdown of the procedure for removing the front axle stub on a CAT 70 scraper:

1. Prepare the Work Area
   Start by parking the scraper on a level surface. Engage the parking brake and ensure the scraper is powered off. It’s also a good idea to disconnect the battery to avoid any electrical accidents during the process.
   
2. Lift the Front End of the Scraper
   Use a hydraulic jack to lift the front end of the scraper. Ensure that the machine is stable by placing safety stands underneath. This will give you access to the axle and make the removal process easier.
   
3. Remove the Front Wheels
   Begin by removing the front wheels to gain access to the axle stub. Use a lug wrench to loosen the wheel nuts, and then safely remove the wheels from the axle. Store them in a safe place for reinstallation after the stub is replaced or repaired.
   
4. Disassemble the Axle Components
   The next step is to remove any components that are connected to the axle assembly. This may include the brake assemblies, wheel hubs, or other components that might obstruct access to the axle stub. Take note of the order in which components are removed to assist with reassembly.
   
5. Disconnect the Axle Stub
   With the components removed, you should now be able to access the axle stub. Depending on the model of the CAT 70 scraper, the axle stub may be held in place by bolts or retaining clips. Use appropriate tools to disconnect the stub from the axle assembly.
   
6. Use a Puller Tool if Necessary
   If the axle stub is particularly stubborn or has become stuck, you may need to use a puller tool to remove it. The puller tool applies even pressure around the stub, allowing it to break free from any corrosion or damage that may have caused it to become stuck.
   
7. Inspect the Axle Stub and Bearings
   Once the axle stub has been removed, take the time to inspect it for damage or wear. If the bearings are worn or the stub is damaged, it will need to be replaced. You may also want to inspect the surrounding components, such as the wheel hub and brake system, for any signs of damage or wear.
   
8. Reassemble and Test
   After replacing the axle stub or making any necessary repairs, carefully reassemble the scraper in reverse order. Make sure to torque the bolts to the manufacturer's specifications and check that all components are securely attached. Once reassembled, test the scraper to ensure that the axle functions properly and there are no unusual sounds or issues with the steering.
   

Common Issues When Pulling the Front Axle Stub
While removing the front axle stub, you may encounter several issues that could complicate the process:

1. Stubborn or Seized Components
   Over time, moisture and dirt can cause parts to become seized or corroded. If you find that the axle stub is difficult to remove, applying penetrating oil to the affected area and allowing it to sit for a few hours may help.
   
2. Damaged Threads or Bolts
   If the bolts that secure the axle stub are stripped or damaged, you may need to replace them or use an extractor tool to remove them without causing further damage.
   
3. Alignment Issues
   When reinstalling the axle stub, ensure that it is aligned properly with the axle housing. Misalignment can lead to uneven wear, poor performance, and potential damage to the components.
   

Conclusion: Maintaining Your CAT 70 Scraper for Optimal Performance
Removing and replacing the front axle stub on a CAT 70 scraper is a necessary task that requires careful attention and precision. Whether it’s due to damage, wear and tear, or as part of preventive maintenance, understanding the process will help ensure that your scraper continues to perform at its best.
By following the correct procedure for pulling the axle stub and addressing any issues promptly, you can extend the life of your CAT 70 scraper and avoid costly repairs in the future. Proper maintenance of the axle assembly is key to keeping the machine running smoothly, and regular inspections will help you detect problems early before they become major issues.
Always consult the machine’s service manual for the specific details of your model, as procedures may vary slightly depending on the year and configuration.