Bobcat 4-in-1 Combo Bucket Bent Bowed Suggestions to Fix

[MikePhua]

Overview of the Issue
Owners of Bobcat 4-in-1 combo buckets occasionally encounter bending or bowing—especially along the middle—resulting in misalignment where the bucket fails to fully close or becomes deformed. This "smiling" appearance not only restricts functionality but can compromise the attachment’s integrity over time. Common underlying causes include excessive stress during work, thinner steel floor plates, or insufficient structural support.
Practical Methods to Straighten a Bent Combo Bucket
Drawing from field-proven repair techniques, here's a breakdown of effective strategies—translated into my own words and enriched with technical explanation:

• I-Beam plus Hydraulic Jack Method
  • Use a sturdy I-beam aligned underneath the bucket’s bowed section as a straight-back foundation.
    
  • Chain or clamp the bucket securely to the beam to prevent slippage.
    
  • Position a heavy-duty hydraulic bottle jack—commonly 20-ton capacity—between beam and bucket.
    
  • Apply pressure gradually and evenly, allowing the bowed metal to revert toward its original shape. Slight over-bending is recommended to account for material spring-back during release.
    
  • This method avoids heat, reducing distortion risks. It’s straightforward, safe when executed carefully, and has a strong track record .
    
• Plasma-Cut Slots and Re-Shape Technique
  • Cut partial-thickness slots—around three-quarters through the steel—strategically along the bent region to introduce controlled flexibility.
    
  • Press with hydraulic force to achieve desired alignment.
    
  • Weld the slots closed using appropriate welding rods (e.g., 7014 stick) for structural integrity.
    
  • This enables precise reshaping and enhances results when the original metal resists deformation .
    
• Flame Straightening
  • Heat a narrow, targeted area using oxy-acetylene, then allow it to cool rapidly.
    
  • The contraction from cooling helps remove distortions due to stretched metal.
    
  • Effective when bending is minor and access to flame tools is feasible. Requires expertise—otherwise, risk of uneven warping is high .
    
• DIY Timber + Chain + Jack Method
  • Use heavy timber atop the bucket, wrap chains around the bowed section, and place a hydraulic jack over the assembly.
    
  • Gradually press the buckled area back into alignment.
    
  • It's low-cost and accessible—handlers have noted it often suffices without resorting to heat .
    

Examples from the Field

• A workshop owner shared how he found a heavy-duty 60-inch 4-in-1 bucket, more robust than stock, and carefully cut slots with a plasma cutter to facilitate straightening. He then used a 20-ton air-over-hydraulic jack. After pressing and slightly over-bending, he welded the slots back together, achieving near-flat cutting edges. The project even turned a profit when resold .
  
• A farmer-repairer in Australia revived a bent bucket using a length-matched I-beam and a 20+ ton jack. No heat was needed. Chains held everything securely, and with patience, the bucket regained its alignment .
  

Repair Alternatives and Safety Tips

• Cut and Re-Weld
  • If bending is severe, cut out the deformed area, clamp it to a straight reference, then re-weld. This restores alignment and avoids dangerous distortion .
    
• Take Caution
  • Always position equipment to avoid pinch points.
    
  • Use gear rated adequately for force—chains, jacks, and beams must match the load.
    
  • Apply pressure slowly, checking progress and stopping before structural stress becomes critical.
    
  • When using heat, apply widely and evenly—localized overheated spots can curve unpredictably.
    

Step-by-Step Guide (Summarized)

1. Assess damage—measure deformation; determine if it's bend, twist, or both.
   
2. Select method—gentle cases: jack + I-beam or jack + timber; severe: plasma slots or cut-and-reweld.
   
3. Set up—secure bucket to beam or timber, place jack properly.
   
4. Apply force gradually—monitor shape changes; over-bend slightly to allow spring-back.
   
5. Secure final shape—weld slots or re-weld joints; grind/finish surface.
   
6. Test operation—ensure bucket now closes properly and functions under light load before full use.
   

Terminology Quick-Reference

• 4-in-1 Combo Bucket: Loader attachment with tilting functions—open (clamshell), close (bucket), standard, and scrape modes.
  
• Bowing / Smiling: Curvature across bucket face resembling a smile; common misalignment.
  
• I-Beam: A structural steel beam (I-shaped) used to support straightening works.
  
• Bottle Jack: A compact hydraulic jack, often rated 20 tons or more, for applying direct force.
  
• Spring-Back: Elastic recovery of steel after bending—requires overcompensation during straightening.
  
• Plasma Cutter: Tool that cuts metal using a high-temperature plasma arc for precision cutting.
  
• Flame Straightening: Using heat expansion and controlled contraction to reshape steel.
  

Bobcat Company Brief Background

• Origins: Began in the late 1950s when the Keller brothers built a compact loader to clean turkey barns—leading to the first Melroe skid-steer production .
  
• Growth Milestones:
  • 1957–58: Only a few loaders built.
  • 1960–62: First skid-steer (M400), then the Bobcat-branded M440.
  • 1969: 10,000 loaders built; 1980: 100,000; 2001: 500,000; 2014: 1,000,000 .
  
• Sales Share: Around 25% of new skid-steer sales recently; leading in both new and used markets .
  
• Corporate Evolution: Originally Melroe Manufacturing, acquired by Clark (1969), then Ingersoll-Rand (1995), and finally Doosan in 2007. Despite corporate changes, Bobcat remains a dominant compact equipment brand .
  

Conclusion
Straightening a bent Bobcat 4-in-1 combo bucket is both practical and achievable with the right approach. For many, using an I-beam and a 20-ton jack offers a reliable, non-thermal solution. For tougher cases, combining plasma-cut flexibility with welding brings precision. Heat-based methods work too but require experience. Safety and patience are paramount throughout the process.
Having initial data on Bobcat’s company heritage, sales scale, and brand reputation helps place the repair in context: this is well-engineered hardware with global reach—worthy of careful maintenance and restoration.