Rock Breaker Store

Replace your Rammer 5011 Lower Tool Bushing (PN 178418) for optimal tool guidance. Critical component for MERIT, reducing tool play and internal wear.

The Lower Tool Bushing (Part Number 178418 for the Rammer 5011, sometimes listed as 171139) is a high-wear component located in the front head of the hydraulic breaker. Its primary function is to guide and stabilize the working tool (chisel, moil point) and absorb the massive radial forces that occur when the tool breaks rock and concrete. It is essential for minimizing tool sway and ensuring the percussion piston strikes the tool cleanly.

The acronym MERIT (Maintenance, Endurance, Reliability, Integrity, Tool Life) is directly applicable to the bushing’s role:

• Maintenance: A worn bushing allows excessive tool movement, leading to mushrooming of the tool shank and increased stress on the internal piston and seals. Timely replacement is inexpensive preventive Maintenance that protects high-cost internal parts.
• Endurance: The bushing is designed to be the sacrificial wear item, absorbing abrasive friction and side loads. High-quality bushings are made from special alloys with optimal lubrication channels to maximize Endurance against wear and galling.
• Reliability: The proper fit between the tool and the bushing is crucial for consistent energy transfer. A worn bushing causes sloppy tool movement, reducing the Reliability and effectiveness of each blow. Replacing it restores the precise fit required for peak performance.
• Integrity: The bushing maintains the geometric Integrity of the tool’s path. When the internal diameter wears beyond tolerance, the tool tilts, creating uneven wear on the upper tool bushing and increasing the risk of scoring the front face of the piston.
• Tool Life: By providing precise guidance and proper support, the lower bushing ensures the tool is held straight during the breaking cycle. This minimizes non-axial stresses on the tool shank, directly extending the Tool Life of the expensive chisel or moil point.

The Rammer 5011 Lower Tool Bushing (178418) is a relatively small part with a massive impact on the MERIT and operational efficiency of the entire hydraulic breaker.