Takeuchi TB135 Thumb Installation and Performance

[MikePhua]

History and Background of the TB135
The Takeuchi TB135 compact excavator was introduced in the early 2000s as part of Takeuchi’s growing lineup of mini and mid-sized excavators. Takeuchi, a Japanese company founded in 1963, pioneered the mini excavator concept and brought the first compact hydraulic excavator to market in 1971. By the time the TB135 was launched, Takeuchi had already established itself as a leader in compact construction equipment, with sales expanding rapidly across Europe, North America, and Asia. The TB135 became a popular model due to its versatility, with an operating weight of approximately 3.5 tons and an engine output around 29–30 horsepower. Its compact frame and zero-tail swing design made it ideal for urban construction, landscaping, and utility work. Tens of thousands of TB135 units have been sold worldwide, with many still active in fleets today.
Role of a Hydraulic Thumb
A hydraulic thumb is an attachment designed to work with the bucket, allowing the excavator to grab, hold, and manipulate objects such as logs, rocks, or demolition debris. Unlike a static mechanical thumb, a hydraulic version connects to the machine’s auxiliary hydraulics and is controlled from within the cab. For compact excavators like the TB135, adding a thumb significantly increases versatility, essentially converting the machine into a multifunctional tool handler rather than just an earthmover.
Key Components Involved in Installation
Installing a thumb on the TB135 requires several major elements:

• Thumb assembly: The welded steel arm fitted with teeth to grip material.
  
• Hydraulic cylinder: Provides actuation force to open and close the thumb.
  
• Mounting bracket and pins: Secure the thumb to the stick or dipper arm.
  
• Auxiliary hydraulic circuit: Supplies pressurized oil to operate the thumb cylinder.
  
• Control valve and switch: Allows the operator to extend and retract the thumb on demand.
  

The TB135 is factory-prepared with optional auxiliary hydraulics, but retrofitting often requires routing new hoses and ensuring compatibility with the existing control system.
Installation Process
The installation process can be broken down into several stages:

1. Preparation – Confirm the machine has auxiliary hydraulic ports or install an aftermarket auxiliary kit.
   
2. Mounting the thumb – Weld or bolt the base plate to the stick. Accurate alignment is crucial to ensure the thumb closes flush with the bucket.
   
3. Cylinder attachment – Install the hydraulic cylinder and secure it with pins to both the thumb and the mounting bracket.
   
4. Hydraulic hookup – Connect hoses to the auxiliary ports, ensuring correct routing to avoid pinch points.
   
5. Control integration – Install an in-cab switch or joystick button to control thumb movement.
   
6. Testing – Cycle the thumb through its full range, checking for leaks, interference, and proper synchronization with the bucket.
   

Operational Considerations
When properly installed, the thumb on a TB135 allows the operator to:

• Pick and place irregular loads such as rocks, logs, or scrap.
  
• Assist in demolition tasks by grabbing debris.
  
• Reduce reliance on ground labor, improving site safety.
  
• Increase productivity by handling multiple functions without additional equipment.
  

Field data from equipment rental companies shows that machines with hydraulic thumbs are 25–30% more likely to be rented compared to those without, due to their versatility.
Maintenance of the Thumb System
Like other hydraulic attachments, the thumb requires periodic inspection and service:

• Check hydraulic hoses regularly for abrasion or leaks.
  
• Inspect pivot pins and grease them to reduce wear.
  
• Monitor cylinder seals for signs of leakage or bypassing.
  
• Test control valve responsiveness to prevent sluggish actuation.
  

Preventive maintenance significantly extends the lifespan of the attachment and ensures consistent performance.
Real-World Example
On a utility project in Texas, a contractor reported a 40% increase in productivity after fitting a TB135 with a hydraulic thumb. The operator was able to remove old concrete sidewalk panels and place them directly into trucks without manual labor. The thumb’s ability to grip and rotate irregular shapes reduced downtime and eliminated the need for a second machine.
Industry Context and Safety Notes
Hydraulic thumbs have become increasingly standard on compact and mid-size excavators. Industry surveys suggest that over 60% of compact excavators sold in North America are now delivered with thumbs, either factory-installed or dealer-added. This reflects a broader trend toward multi-functionality in compact construction equipment. However, safety remains critical: improper installation or mismatched hydraulics can lead to uncontrolled movements, potentially causing accidents. Technicians recommend pressure testing the hydraulic circuit after installation and training operators on proper use to avoid overloading the thumb.
Conclusion
The Takeuchi TB135, already a versatile and durable compact excavator, becomes even more effective when fitted with a hydraulic thumb. The installation requires careful attention to hydraulic connections, alignment, and control integration, but the payoff is significant—improved productivity, reduced labor, and increased machine utilization. For contractors and fleet managers, investing in a thumb-equipped TB135 is not just about adding a feature, but about transforming the excavator into a multipurpose work tool capable of handling a wide variety of tasks with precision and efficiency.