646288 - TCM Continental Motors OEM Crankshaft Thrust Washer

646288 – TCM Continental Motors OEM Crankshaft Thrust Washer

Available now on the Airparts.aero Marketplace.

Overview

The Continental 646288 is a genuine OEM crankshaft thrust washer, a precision-engineered component that serves a flight-critical role within the engine's rotating assembly. This washer is designed to absorb and control the axial (fore and aft) loads placed upon the crankshaft, a force known as "thrust." By precisely managing crankshaft end play, the 646288 ensures that the crankshaft remains perfectly positioned within the crankcase, preventing catastrophic damage to the case, bearings, and other internal components. Manufactured from a specialized bi-metallic material, this washer is an essential, high-wear component that is mandatory to inspect and replace during engine overhaul.

Key Features

• Controls Crankshaft End Play: Its primary function is to set and maintain the axial clearance of the crankshaft. This is critical for accommodating thermal expansion and for managing the significant thrust loads generated by the propeller.
• Bi-Metallic Construction: Features a strong steel backing for structural integrity, bonded to a soft bearing alloy surface (typically a lead-bronze or similar material). This soft layer provides a low-friction, sacrificial wear surface against the crankshaft cheek.
• Precision Thickness: Manufactured to extremely tight thickness tolerances. This precision is what allows a mechanic to set the crankshaft end play to the exact specifications called for in the engine overhaul manual (e.g., 0.004" to 0.011").
• Oil-Guiding Design: Often incorporates specific channels or features designed to direct lubricating oil to the thrust faces, ensuring a constant hydrodynamic film of oil to prevent metal-to-metal contact.
• Genuine Continental OEM Part: Guarantees the use of the correct materials and manufacturing processes as specified by the engine's original type certificate, ensuring proper performance, wear characteristics, and airworthiness.

Technical Specifications

• Part Number: 646288
• Component Type: Crankshaft Thrust Washer
• Function: Control of crankshaft axial thrust and end play
• Material: Steel-backed bearing alloy
• Installation Location: Fits into a machined recess in the front main bearing journal of the crankcase.
• Critical Dimension: Thickness (used to set end play)
• Certification: FAA Production Approval

Engine Compatibility

The Continental 646288 thrust washer is a common part used across a wide variety of Continental's most successful engine families, from mid-size to large-bore. Verifying the correct part number in the specific engine's Illustrated Parts Catalog (IPC) is always required.

• Compatible Engine Series:
  • O-470, IO-470, TSIO-470
  • IO-520, TSIO-520
  • GTSIO-520
  • IO-550, TSIO-550

Applications

The 646288 thrust washer has a singular but profoundly important application:

• Engine Rotating Assembly: Serves as the primary wear surface for all axial loads imparted on the crankshaft by the propeller, especially in tractor (puller) propeller configurations.
• Mandatory Overhaul Component: This washer must be inspected for wear and damage during any engine teardown. It is almost always replaced during a major overhaul to reset the crankshaft end play to factory specifications.

Why Choose 646288?

Incorrect crankshaft end play can lead to a host of severe engine problems, from improper oil pressure to crankcase fretting and even catastrophic failure of the crankshaft. Using a genuine Continental 646288 OEM thrust washer is the only way to ensure you are installing a part with the correct material composition and precise thickness needed for this critical task. The integrity of the entire engine rotating assembly depends on the quality of this single component. For professional engine builders and mechanics, there is no substitute for the certified quality and guaranteed fit of a genuine Continental part.

Order Your 646288 Thrust Washer Now

Ensure the precision and longevity of your engine overhaul with a genuine Continental 646288 crankshaft thrust washer. Visit Airparts.aero to order this essential OEM component today.

The Continental 646288 thrust washer is a hydrodynamic bearing designed to operate under axial load. During engine operation, the propeller is constantly pulling the crankshaft forward. This thrust load is transferred from a machined cheek on the crankshaft to the face of the 646288 washer. A pressurized film of oil is maintained between these two surfaces, preventing direct metal-to-metal contact. The clearance, or "end play," set by this washer's thickness is critical; too little, and thermal expansion could cause the bearing to bind and fail. Too much, and the crankshaft can hammer back and forth, damaging the crankcase and disrupting the precise gear mesh at the rear of the engine. The installation and measurement of this washer using a dial indicator is a foundational step in any professional engine assembly, directly impacting the engine's performance, smoothness, and ultimate service life.

Note: This is a critical engine internal component. Installation must be performed by a certified A&P mechanic during engine assembly in strict accordance with the procedures and specifications outlined in the current Continental Motors Overhaul Manual for the specific engine model.

Description: Crankshaft Thrust Washer
Part Number: 646288
Superseded by: SA646288
FAA Eligibility [ Click Here ]
Superior PMA Number [ 63-R2 ]
Alternate Part Numbers: AEC646288, SA646288, SA646288STD, 628136

Product Overview

An item of any peripheral shape usually having one flat or spherical surface and a centrally located hole. It is designed for applications involving moving (kinetic) loads. Except for items fabricated from bearing quality synthetic (plastic) or composed of multilayer material, one bearing surface must either have a specific surface finish designation of 32 micro inch. (0.8 micrometers) or less, arithmetical average (aa) (arithmetic mean deviation), or one of the following conditions: be lapped or ground; have visible or detectable means of lubrication; grooves, indentations; or self-lubrication. The thickness must not exceed 25 percent of the outside diameter of the shortest distance between peripheral flats (when thickness and/or outside diameter is designated as a tolerance dimension, the maximum dimension will be used to determine compliance). Excludes straight, tubular (without flange) items having a bearing surface(s) parallel to the axis of the bore only.

 
Used as engine crankshaft thrust washer.

 
Sets That Includes P/N: SA646288 [ Click Here ]

Fits in Teledyne Continental Engines:

**Continental Motors Inc. Engine Model IO-520 Illustrated Parts Catalog [ Click Here ]

See page 16, Figure 8, Item 14.