Case 1155D Drive Sprocket Replacement: A Step-by-Step Guide

[MikePhua]

Introduction
Replacing the drive sprockets on a Case 1155D is a critical maintenance task for ensuring the proper function of the machine. The drive sprocket is a key component in the final drive system, responsible for transferring the engine’s power to the tracks. Over time, these sprockets wear down, leading to decreased performance and possible track issues. In this guide, we will walk you through the process of replacing the drive sprockets on a Case 1155D.
Symptoms of Worn Drive Sprockets
Before diving into the replacement process, it’s important to identify when your sprockets need replacing. Some common signs of worn or damaged drive sprockets include:

1. Excessive Track Slippage
   If you notice the tracks slipping or failing to grip the ground properly, it could be due to worn sprockets not engaging the track teeth properly.
   
2. Visible Damage or Wear
   Look for visible wear on the teeth of the sprocket. Over time, the teeth can become rounded or cracked, which will affect the machine’s performance.
   
3. Unusual Noise
   If you hear grinding or clunking noises coming from the track area, this could be an indication that the sprocket is not meshing correctly with the track links.
   

Tools Required
Before starting the replacement, ensure you have all the necessary tools and parts:

• Hydraulic jack or track jack
  
• Wrenches and socket set
  
• Torque wrench
  
• New sprockets (make sure they match your Case 1155D model)
  
• Safety gloves and goggles
  

Step-by-Step Process for Sprocket Replacement

1. Safety Precautions
   Begin by ensuring the machine is on a flat and level surface. Engage the parking brake, and turn off the engine. Use safety cones or barriers around the work area to prevent accidents.
   
2. Lift the Machine
   Using a hydraulic jack, carefully lift the machine and support it with track jacks to ensure it remains stable. Make sure the tracks are off the ground, allowing easy access to the drive sprocket area.
   
3. Remove the Track Tension
   Loosen the track tension by adjusting the tensioner. This will help release the pressure on the sprockets and allow for easier removal. Be sure to follow the manufacturer’s instructions on how to release the track tension for your specific machine model.
   
4. Remove the Tracks
   Next, remove the track from the sprocket. You may need to remove bolts or other securing devices that hold the track in place. Depending on the model, you may need to partially disassemble the track to remove it from the sprocket.
   
5. Unbolt the Drive Sprocket
   Once the track is removed, locate the bolts securing the drive sprocket to the final drive assembly. Use a socket wrench to remove these bolts. Be sure to keep the bolts as they will be reused to secure the new sprocket.
   
6. Remove the Old Sprocket
   Carefully slide the old sprocket off the final drive. It may require some force, depending on how tightly it’s attached. If there is any significant corrosion or dirt buildup, clean the area before installing the new sprocket.
   
7. Install the New Sprocket
   Slide the new sprocket into place. Ensure that the teeth of the sprocket are properly aligned with the track links. It’s important to check for proper alignment to prevent uneven wear on the new sprocket.
   
8. Reattach the Sprocket
   Once the new sprocket is in position, use the original bolts to reattach it to the final drive. Tighten the bolts in a crisscross pattern to ensure even pressure. Use a torque wrench to ensure that each bolt is tightened to the manufacturer’s recommended specification.
   
9. Reinstall the Track
   Carefully slide the track back into place, ensuring that it is properly aligned with the new sprocket. Reattach any bolts or components that were removed earlier to secure the track.
   
10. Adjust Track Tension
    

After the track is reinstalled, adjust the track tension to the correct level. This is crucial for ensuring optimal performance and longevity of the tracks and sprockets.

1. Test the Machine
   

Lower the machine back to the ground and perform a thorough inspection to ensure everything is properly reassembled. Start the machine and test the tracks to ensure the new sprocket is functioning correctly. Listen for any unusual sounds, and check the operation of the track system.
Common Issues During Sprocket Replacement

1. Stubborn Sprocket Removal
   If the old sprocket is particularly difficult to remove, it may be due to rust or corrosion. In such cases, apply a penetrating oil to loosen the sprocket and use a pry bar if necessary.
   
2. Incorrect Sprocket Size
   Before purchasing the new sprockets, double-check the size and model compatibility with your Case 1155D. Using the wrong sprocket can lead to improper fit and damage to the tracks or drive system.
   
3. Uneven Track Wear
   After replacing the sprockets, monitor the track for any uneven wear patterns. If the tracks are not tracking straight or the sprockets are showing signs of excessive wear, there may be an issue with the alignment or tension.
   

Conclusion
Replacing the drive sprockets on a Case 1155D is an essential part of routine maintenance. By following this step-by-step guide, you can ensure that the process is done efficiently and correctly. Proper maintenance of the sprockets will help extend the life of your dozer, improve performance, and prevent costly repairs in the future. Always remember to follow safety procedures and consult the manufacturer’s guidelines for best results.