Upgrading Bucket Teeth on Older Machines for Better Digging Performance

[MikePhua]

The Problem with Smooth Cutting Edges
Operators of older backhoes and loaders often face a common issue: smooth bucket edges that struggle to penetrate compacted soil, gravel piles, or hard-packed fill. Machines like the Deere 310A, a two-wheel-drive backhoe from the late 1970s and early 1980s, were typically equipped with bolt-on smooth cutting edges designed for general-purpose scraping and cleanup. While effective for loose material, these edges tend to skate over dense piles, reducing bucket fill and increasing cycle times.
In contrast, compact machines like the Bobcat 753 skid steer—especially when equipped with toothed buckets—can dig aggressively into the same material. This difference in performance has led many operators to explore retrofitting their older machines with bolt-on or weld-on bucket teeth.
Terminology Annotation

• Cutting edge: The lower front edge of a bucket that contacts the ground during digging or scraping.
  
• Tooth bar: A removable bar with pre-mounted teeth that bolts onto the bucket’s cutting edge.
  
• Shank: The base component welded or bolted to the bucket, onto which the tooth is mounted.
  
• Series 23 teeth: A common tooth size used in light to medium-duty applications, known for affordability and availability.
  

Tooth Options for Legacy Buckets
There are several approaches to adding teeth to older buckets:

• Bolt-on tooth bars: These are preassembled bars with teeth that bolt directly to the existing cutting edge. They’re ideal for operators who want to retain the ability to switch back to a smooth edge for cleanup work.
  
• Weld-on shanks and replaceable teeth: This method involves welding shanks to the bucket and installing individual teeth. It offers a more permanent solution and allows for customized spacing.
  
• Hybrid systems: Some operators fabricate custom adapters using flat bar stock and sections of cutting edge steel, bolting them through existing holes. These setups can be surprisingly effective and cost-efficient.
  

One operator reported fabricating five teeth for a 9-foot loader bucket using 4-inch wide flat bar and bolt-through retention. The result was a dramatic improvement in digging virgin soil, with the added benefit of quick removal for stockpile work.
Performance Gains and Practical Considerations
Adding teeth to a smooth bucket can transform machine performance. Teeth concentrate force into smaller contact points, allowing the bucket to break into compacted material more easily. This is especially useful for:

• Digging into hard-packed fill or virgin soil
  
• Breaking up sod or clay
  
• Excavating gravel or frozen ground
  

However, there are trade-offs. Teeth can reduce the bucket’s ability to scrape clean surfaces like concrete or asphalt. They also introduce stress concentrations that may deform older buckets not designed for aggressive digging.
Recommendations:

• Use 6-inch wide by 5/8-inch thick bolt-on cutting edges as a base
  
• Water jet cut holes for Series 23 shanks to ensure precision
  
• Space teeth 9–12 inches apart for balanced force distribution
  
• Reinforce the bucket lip if signs of flexing or bowing appear
  

Cost Estimates and Sourcing
A typical retrofit might cost:

• $300 for a predrilled cutting edge
  
• $200 for Series 23 teeth and shanks
  
• $50–100 for welding or fabrication labor
  

Total investment: ~$500 for a full upgrade. Many operators find this cost justified by the increase in productivity and reduced wear on the machine.
Series 23 teeth are widely available and used across multiple brands, making them a reliable choice for retrofits. Some dealers offer preassembled kits, while others sell components individually.
Operator Techniques and Machine Limitations
While teeth improve penetration, operator technique remains critical. Machines like the 2WD Deere 310A lack the torque converter and traction of newer 4WD models. Learning to “shave” the pile—entering with a flat bucket angle and curling upward gradually—can maximize fill without overloading the transmission.
Tire chains and proper ballast also help improve traction when pushing into piles. In some cases, replacing the light-duty cutting edge with a heavier one before adding teeth can prevent structural damage.
Historical Context and Equipment Evolution
The Deere 310A was part of John Deere’s early backhoe loader series, introduced in the late 1970s. It featured a naturally aspirated 4-cylinder diesel engine and manual transmission. While reliable, its loader performance was limited compared to later models like the 310C, which introduced torque converters and improved hydraulics.
Bobcat’s 753 skid steer, launched in the 1990s, offered hydrostatic drive and quick-attach buckets, making it a versatile tool for landscaping and light excavation. Its compact size and aggressive digging ability made it a favorite among contractors and rental fleets.
Conclusion
Retrofitting bucket teeth on older machines like the Deere 310A is a practical and cost-effective way to improve digging performance. Whether using bolt-on tooth bars, weld-on shanks, or custom adapters, the upgrade can dramatically increase efficiency in compacted material. With careful planning, proper spacing, and attention to bucket integrity, operators can breathe new life into legacy equipment and tackle tougher jobs with confidence.