71481 - Lycoming Engines OEM Oil Ring Seal .09 Diameter x 4.84 Internal Diameter

71481 – Lycoming Engines OEM Oil Ring Seal

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Overview

The Lycoming 71481 is a genuine OEM, flight-critical oil ring seal, engineered for a variety of sealing applications on Lycoming's most popular piston engines. This is not a standard O-ring; it is a precision-molded packing seal designed to create a positive, durable barrier against hot, high-pressure engine oil. Its most common and critical application is as the crankshaft oil seal located in the engine's accessory case. Fabricated from a specialized, high-temperature synthetic rubber, the 71481 is essential for preventing oil leaks from the front of the engine.

Key Features

• Positive Oil Sealing: Its primary function is to create a dynamic or static seal to contain engine lubricating oil. As a crankshaft seal, it prevents oil from leaking from the crankcase past the front of the crankshaft.
• High-Temperature Synthetic Rubber: Manufactured from a specialized synthetic rubber compound formulated to resist degradation, hardening, and swelling when in constant contact with hot engine oil and the high temperatures of the engine compartment.
• Precision Molded Dimensions: Fabricated to extremely tight tolerances for cross-sectional diameter and inside diameter. This precision is essential to ensure a perfect fit in its designated groove, providing the correct amount of sealing force.
• Compression Set Resistance: The material is formulated to resist "compression set"—the tendency of a rubber seal to permanently flatten over time when compressed. This ensures the seal maintains its elasticity and sealing capability for its full service life.
• Genuine Lycoming OEM Part: As a genuine factory component, it guarantees the correct material composition, durometer (hardness), and dimensional tolerances required for a long-lasting, leak-free seal as specified by the engine's original designers.

Technical Specifications

• Part Number: 71481
• Component Type: Oil Ring Seal / Packing
• Material: High-Temperature, Oil-Resistant Synthetic Rubber
• Nominal Dimensions:
  • Inside Diameter: 4.844 inches
  • Cross Section Diameter: 0.090 inches
• Primary Application: Crankshaft Oil Seal (in accessory case) and other locations.
• Certification: FAA Production Approval

Aircraft Compatibility

The Lycoming 71481 is a critical sealing component used on a vast number of Lycoming's 4- and 6-cylinder direct-drive engines.

• Common Lycoming Engine Series:
  • O-320, IO-320, LIO-320, AIO-320, AEIO-320
  • O-360, IO-360, LIO-360, AIO-360, AEIO-360
  • O-540, IO-540, TIO-540, AEIO-540
• Common Aircraft Platforms:
  • A vast range of aircraft from Piper, Cessna, Beechcraft, Mooney, and numerous experimental designs that utilize the above Lycoming engine series.

Applications

The 71481 is an essential component for engine maintenance and overhaul:

• Engine Overhaul: A mandatory replacement item during any engine overhaul or when the accessory case is removed from the crankcase.
• Oil Leak Repair: The primary component to replace when troubleshooting oil leaks originating from the front crankshaft seal area or other locations where it is specified.
• Preventative Maintenance: Replacing this seal during major maintenance is a key preventative action to avoid future oil leaks.

Why Choose 71481?

An oil leak from a primary engine seal, such as the crankshaft seal, is a serious issue that can coat the engine and windscreen in oil, create a fire hazard, and lead to significant oil loss. The Lycoming 71481 is the genuine, factory-specified seal designed to prevent this. Using an OEM part ensures the seal is made from the correct, high-temperature material that will not prematurely harden or shrink. For a clean, reliable, and airworthy engine, there is no substitute for genuine Lycoming seals.

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• Meta Title: 71481 Lycoming Crankshaft Oil Ring Seal | OEM | Airparts.aero
• Meta Description: Purchase the genuine Lycoming 71481 oil ring seal. A flight-critical, high-temperature rubber packing for the crankshaft and other applications on Lycoming O-320, O-360, and IO-540 series engines.
• SEO and Plain Text Keywords: 71481, Lycoming parts, crankshaft seal, oil ring seal, engine gasket, Lycoming seal, O-360 parts, IO-540 parts, aircraft engine parts, oil leak, OEM Lycoming parts, Airparts.aero.

Order Your Lycoming 71481 Seals Now

Ensure a clean, leak-free engine with genuine, factory-certified Lycoming seals. Visit Airparts.aero to order your 71481 oil ring seals today.

SEO-Enhanced Addendum

The 71481 seal, when used as a crankshaft seal in the accessory case, functions as a critical barrier in the engine's lubrication system. The front of the crankshaft passes through the accessory case to drive the propeller governor and other components. The 71481 is typically installed in a groove in the accessory housing and seals against a dedicated surface on the crankshaft itself. It must contain the pressurized "splash" oil within the crankcase while enduring the constant high-speed rotation of the crankshaft. The seal's material must be able to maintain a positive seal without causing excessive friction or wear on the crankshaft's sealing surface, a balance achieved through precise material engineering by the OEM.

Note: This is a flight-critical engine component. Installation must be performed by a certified A&P mechanic, typically during engine overhaul or major repair, in strict accordance with the current Lycoming Overhaul Manual. All sealing surfaces must be meticulously clean and free of nicks or scratches before installation. Care must be taken during installation to not damage the seal.