Overview
The Lycoming Rocker Arm, part number LW-18476, is a critical component within the valve train system of various Lycoming IO-360 and AIO-360 series aircraft engines. This precisely engineered part serves to transmit the linear motion of the pushrod into a pivotal action, opening the intake or exhaust valve at the appropriate phase of the engine cycle. Positioned on a rocker shaft, the rocker arm pivots to depress the valve stem, allowing for the controlled flow of gases into and out of the combustion chamber. Its robust construction is essential for enduring the repetitive stresses and temperatures inherent to internal combustion engine operation, directly impacting engine performance and longevity.Specifications
This Lycoming rocker arm, P/N LW-18476, is manufactured to exacting standards to ensure reliable operation within its demanding environment. While precise weight and dimensional specifications can vary slightly between production batches and are typically detailed in Lycoming's official engineering drawings, the general characteristics are as follows:- Material: Typically forged steel alloy, heat-treated for optimal strength, wear resistance, and fatigue life.
- Finish: Often features a phosphate coating or oil impregnation for corrosion resistance and reduced friction during initial break-in.
- Design: Features a spherical cup for the pushrod end, a bore for mounting on the rocker shaft, and a pad designed to contact the valve stem tip.
- Weight: A lightweight, yet durable component, generally weighing a few ounces (specific weight is not publicly cataloged without proprietary engineering data).
- Dimensions: Compact, designed to fit precisely within the cylinder head's rocker box area (exact dimensions are proprietary Lycoming data).
- Lubrication: Designed for
- Stock: Out of Stock - On Backorder
- Manufacturer Part #: LW-18476
- Part#: LW-18476
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Returns & refund summary
- 30-day return window — with prior return authorization, unopened in original packaging.
- Restocking fee: 20% on unopened items, 30% on open-box items.
- Refund processing fee: 5.51% applies to all refunds (returns, cancellations, core-fee refunds) regardless of reason.
- Return shipping: paid by buyer.
- Non-returnable categories: installed/used parts, special-order or rebuilt items, programmed items (incl. ELTs), batteries, AOG-priority orders, international orders.
Full terms: Return Policy.
Authenticity & authorization
All parts sold by American Aviation Parts are genuine factory products sourced through authorized distribution channels. Our authorization status varies by brand — for some brands we are a direct authorized dealer; for others we are an independent reseller through authorized distribution. Either way, the part you receive is the same factory product, with standard documentation available on request.
See our full Manufacturer Authorizations page for the current per-brand status.
Need traceability paperwork?
If your installation requires FAA Form 8130-3, manufacturer Certificate of Conformance, or other traceability documentation, please call 1-877-722-8727 or email [email protected] before placing the order so we can confirm what is available for this part.
Shipping
Standard ground, expedited, and AOG shipping options are available at checkout. Full shipping-cost tiers and timelines are published on our Delivery Information page.
