Vibration Issues in Small Excavators: Focus on the Hitachi ZX35U and Deere 35G

[MikePhua]

Small excavators are essential pieces of machinery in construction, landscaping, and utility work, offering a blend of agility and power for a wide range of tasks. Among the popular models in this class are the 2014 Hitachi ZX35U and Deere 35G, both known for their reliable performance in tight spaces. However, even the most well-designed machines can face issues, and one common problem reported with these models is idle vibration. This article will explore the causes of vibration issues in these small excavators, potential solutions, and maintenance tips to ensure smooth operation.
Overview of the Hitachi ZX35U and Deere 35G
The Hitachi ZX35U and Deere 35G are part of the smaller range of excavators that are used extensively in urban construction, utility work, and residential landscaping. These machines are built to provide high maneuverability, a compact design, and strong lifting power for tasks such as trenching, digging, and lifting.
Hitachi ZX35U Specifications:

• Engine Power: 24.4 kW (32.7 hp)
  
• Operating Weight: Around 3,500 kg (7,700 lbs)
  
• Max Digging Depth: 3.2 meters (10.5 feet)
  
• Max Reach: 5.7 meters (18.7 feet)
  

Deere 35G Specifications:

• Engine Power: 26.7 kW (35.8 hp)
  
• Operating Weight: Around 3,500 kg (7,700 lbs)
  
• Max Digging Depth: 3.2 meters (10.5 feet)
  
• Max Reach: 5.7 meters (18.7 feet)
  

Both machines feature strong hydraulics and a durable undercarriage, designed for extended hours of operation in harsh environments. However, one issue that sometimes arises is vibration at idle, which can affect operator comfort and machine efficiency.
Understanding the Idle Vibration Issue
Idle vibration is when the machine experiences excessive shaking or movement while its engine is running but the machine is not actively performing tasks such as digging or lifting. This issue can cause discomfort for the operator and, over time, lead to potential damage to internal components. There are several possible reasons for idle vibration in the Hitachi ZX35U and Deere 35G.
Possible Causes of Idle Vibration

1. Engine Mounting Issues
   • Description: If the engine mounts are worn or damaged, they can fail to absorb the vibrations produced by the engine. As a result, these vibrations are transferred to the machine's frame and can cause noticeable shaking at idle.
     
   • Solution: Inspect the engine mounts for wear or damage and replace them if necessary. This is a relatively easy fix that can significantly reduce idle vibrations.
     
2. Excessive Idling or Low Idle Speed
   • Description: Prolonged idling or an improperly set idle speed can contribute to irregular engine performance, which may lead to vibration. Many modern engines have a default idle speed that can be fine-tuned to suit specific operating conditions.
     
   • Solution: Check the idle speed setting on the machine. Consult the operator's manual for the recommended idle speed. If the idle speed is too low, adjusting it to the optimal level may reduce vibrations.
     
3. Hydraulic System Pressure Imbalances
   • Description: The hydraulic system in excavators plays a key role in controlling attachments, but if the hydraulic fluid pressure is too high or too low, it can cause vibrations, especially when the system is not under load.
     
   • Solution: Inspect the hydraulic fluid levels and pressure settings. Low fluid levels, air in the system, or faulty valves can lead to uneven pressure distribution. Flushing the hydraulic system and refilling with the recommended fluid type can help alleviate the issue.
     
4. Worn or Misaligned Components
   • Description: Worn parts such as the drive belts, pulleys, and linkage can cause vibrations, especially when the machine is idling. Misalignment of components can lead to uneven rotation and imbalance.
     
   • Solution: Regularly inspect all mechanical components for wear or misalignment. If any part appears damaged or out of alignment, replace or realign it. This will not only reduce vibration but also improve the overall performance of the machine.
     
5. Inadequate Fuel Quality
   • Description: Poor-quality fuel or fuel contamination can lead to irregular combustion and engine performance, resulting in vibrations, especially when the machine is not under load.
     
   • Solution: Ensure that high-quality fuel is used in the machine, and regularly change fuel filters. If fuel contamination is suspected, perform a thorough inspection and clean the fuel system.
     
6. Exhaust System Issues
   • Description: A malfunctioning or clogged exhaust system can cause engine backpressure, leading to rough engine performance and vibrations. This can occur in any engine, but it’s particularly noticeable when the machine is idling.
     
   • Solution: Check the exhaust system for any blockages or leaks. Cleaning or replacing the exhaust system components can reduce vibration and improve engine efficiency.
     
7. Tire and Track Condition
   • Description: While not directly related to the engine, the condition of the tires or tracks can influence vibrations, especially when the machine is stationary but running.
     
   • Solution: Check the tracks or tires for wear, uneven tread, or damage. Uneven wear can lead to imbalance, which may cause vibrations. Repair or replace tires/tracks if necessary.
     

Maintenance Tips to Reduce Idle Vibration
Preventing idle vibration starts with proper maintenance. Regular checks and timely repairs can help reduce the chances of vibration and improve the lifespan of the machine.

1. Regularly Check Engine Mounts: Worn engine mounts are one of the most common causes of idle vibration. Replace engine mounts at the first sign of wear to keep vibrations at bay.
   
2. Keep the Hydraulic System in Top Shape: Regularly inspect the hydraulic fluid levels and replace filters as per the manufacturer's recommendations. Clean and flush the system as necessary to avoid pressure imbalances.
   
3. Maintain Proper Fuel Quality: Use only high-quality diesel and ensure that fuel filters are clean and functioning properly. This reduces the risk of engine misfires and vibrations.
   
4. Check and Align Mechanical Components: Make sure all belts, pulleys, and other components are in good condition and properly aligned. Tighten or replace any parts that appear loose or damaged.
   
5. Optimize Idle Speed: Check the machine’s idle speed regularly and adjust it to the manufacturer’s recommended settings. A properly adjusted idle speed will not only reduce vibration but will also save fuel.
   

Conclusion
Idle vibration in small excavators like the Hitachi ZX35U and Deere 35G can be a frustrating issue for operators, but it is typically a sign of an underlying problem that can be addressed with proper maintenance and timely repairs. By identifying the causes of vibration, such as worn engine mounts, hydraulic system imbalances, or mechanical wear, operators can take steps to eliminate the issue and improve the machine’s performance. Regular inspections, maintenance, and quality fuel are key to keeping these compact yet powerful machines running smoothly, ensuring productivity on the job site and extending the machine’s operational lifespan.