Fasco FM55 Universal 3-Leg Torsion-Flex Mounting Bracket Kit | Fits 5.5" Diameter Motors | 9" & 10.18" Bolt Circles 

The Fasco FM55 is the essential mechanical interface between your blower motor and the furnace housing, acting as the structural dampener for your entire air delivery system. This OEM-authorized torsion-flex kit is engineered to serve as the stable "cradle" for 5.5-inch diameter (5-5/8" frame) motors, isolating the high-speed rotational energy from the thin metal of the blower cabinet. By effectively managing these torsional vibrations, the FM55 prevents the system from becoming a sounding board for motor hum, significantly reducing noise in the living space. Whether you are replacing a failed direct-drive motor or upgrading an older Carrier, Trane, or Rheem series unit, this bracket provides the precise alignment needed to protect both the motor bearings and the housing integrity. 

Key Features

• Genuine OEM Part # FM55: Factory-authorized replacement part that ensures exact physical fitment and material quality, eliminating the structural risks of generic aftermarket brackets.
• Dual Bolt Circle Versatility: Features a universal mounting design with both 9-inch and 10.18-inch bolt circles, allowing it to adapt to various furnace and air handler blower housings.
• Torsion-Flex Vibration Isolation: Specifically designed with a 3-leg torsion-flex arrangement to fix issues with cabinet rattling and resonant noise transmission.
• No Preassembly Required: The user-friendly design clamps directly to the motor shell, facilitating a faster installation process without complex hardware configurations.
• Complete Safety Certified Kit: Includes all necessary industrial-grade rubber grommets, washers, and bolts, and carries UL Recognized and CSA Certified safety approvals. 

Product Details

• Brand: Fasco (Regal Rexnord)
• Manufacturer Part #: FM55 (Also referenced as 66483)
• Shipping Weight: 2.03 lbs
• Motor Size Compatibility: 5.5-inch Diameter (5-5/8" Frame)
• Mounting Type: 3-Leg Torsion-Flex
• Bolt Circle Dimensions: 9.0" and 10.18"
• Material: Heavy-duty plated steel
• UPC: 818508022871
• Country of Origin: United States 

🛠️ HVAC Depot Pro Tip

Take a Picture First: Before removing the old bracket, photograph how the legs are oriented relative to the motor's wiring harness and the blower housing vents. This ensures you don't accidentally block the motor's cooling vents or strain the power leads during reinstallation. Diagnostic Check: After clamping the FM55 to the motor shell, ensure the rubber grommets are properly seated in the housing holes before tightening the bolts. Over-tightening can crush the grommets and negate the vibration-dampening benefits of the flex-mount system.

Cross-Reference

• Superseded / Legacy:

  TFM55

• Drawing / OEM Equivalents:

  66483, FM-55

• Brand Equivalents:

  Fits motors from GE, Emerson, Genteq, and AO Smith with 5.5" diameters.

• White-Rodgers/Emerson Equivalents:

  3-Leg Flex-Mount Universal 

Model Compatibility

• Universal Blower Series (Suffixes: 9-Inch BC, 10.18-Inch BC)
• Fasco Direct Drive (Suffixes: D7909, D727, D721, D917, D923)
• Standard 48-Frame Motors (Suffixes: 1/4 HP, 1/3 HP, 1/2 HP, 3/4 HP)