GM Large Trans Mount

The Energy Suspension GM Large Trans Mount (part 3.1129G) is a premium Hyper-Flex polyurethane transmission mount engineered for GM trucks requiring enhanced vibration isolation and durability. This large transmission mount combines interlocking polyurethane construction with a steel backing plate and cadmium-plated fasteners, delivering superior performance compared to stock rubber isolators while maintaining factory geometry and bolt compatibility.

The 7.50-inch transmission bolt span design accommodates a wide range of GM truck platforms, making this a versatile solution for transmission mount replacement across multiple model years and engine configurations. The Hyper-Flex polyurethane compound resists oil degradation, heat cycles, and ozone exposure far more effectively than OEM rubber components, extending service life significantly. The interlocking design prevents deflection under load, reducing unwanted transmission movement that can cause drivetrain vibration, shift harshness, and accelerated wear on surrounding components. The cadmium plating on fasteners ensures corrosion resistance in harsh environmental conditions typical of off-road and agricultural use.

This mount is ideal for truck owners seeking reliable transmission isolation without major modifications. Whether restoring an aging truck, upgrading a fleet vehicle, or building a performance platform, the Energy Suspension large transmission mount provides a cost-effective way to eliminate rubber degradation and improve drivetrain response. Installation is straightforward—the mount drops directly into factory mounting points, requiring no custom fabrication or welding. This kit format includes all necessary hardware for a complete installation.

Energy Suspension has established itself as the market leader in polyurethane suspension and drivetrain isolation for trucks and performance vehicles. The black polyurethane finish combined with the steel plate provides both durability and a clean appearance, whether hidden under the vehicle or visible during maintenance.