{"product_id":"castair-replacement-motor-hub-7-8-shaft-lx78","title":"Castair Replacement Motor Hub, 7\/8\" Shaft LX78","description":"\u003cp\u003eThe Castair Replacement Motor Hub with 7\/8\" Shaft (LX78) fits Cast Air compressor assemblies where the electric motor uses a 7\/8\" diameter output shaft. This is a mid-range shaft size — larger than the 5\/8\" found on the smallest units, but smaller than the 1\" and up sizes used on higher-horsepower models. Before ordering, measure your motor shaft with calipers. A 7\/8\" shaft measures 0.875\" in decimal — if your measurement is different, select the corresponding LX hub for your actual shaft diameter.\u003c\/p\u003e\n\n\u003ch3\u003eWhat the Motor Hub Does\u003c\/h3\u003e\n\u003cp\u003eThe motor hub is the mechanical interface between the electric motor shaft and the compressor pump's drive system. It carries the belt sheave (on belt-driven units) or serves as the coupling interface on direct-drive models. The hub takes the full rotational load of the motor — including the inrush torque spike that happens every time a loaded compressor starts. When this part wears or cracks, the result is vibration, premature bearing wear, belt alignment problems, and eventually a compressor that can't maintain pressure because it can't transfer power properly from motor to pump.\u003c\/p\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e7\/8\" Shaft Bore:\u003c\/strong\u003e Machined to 0.875\" bore diameter for correct fit on compatible motor shafts\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCast Air OEM Part:\u003c\/strong\u003e Factory spec dimensions for compatible Cast Air compressor models\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePrecision Machined:\u003c\/strong\u003e Maintains concentricity between motor shaft and drive assembly\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDirect Replacement:\u003c\/strong\u003e Drops in without modification on compatible units\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e LX78\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eShaft Diameter:\u003c\/strong\u003e 7\/8\" (0.875\")\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eComponent Type:\u003c\/strong\u003e Replacement Motor Hub\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e Cast Air\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePrice:\u003c\/strong\u003e $19.25\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003eNote: Manufacturer's product page was unavailable at time of writing. Confirm compatibility with your Cast Air model number before ordering.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003ch3\u003eWhen You Need This Part\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eHub is cracked, scored, or developing play on the motor shaft\u003c\/li\u003e\n  \u003cli\u003eCompressor vibration is increasing — often first noticed as more noise at startup\u003c\/li\u003e\n  \u003cli\u003eBelt won't stay in alignment despite correct tension and pulley alignment\u003c\/li\u003e\n  \u003cli\u003eMotor replacement — new motor ships with a bare shaft and you need a hub to fit the drive assembly\u003c\/li\u003e\n  \u003cli\u003ePreventive maintenance on a compressor approaching high-hour service intervals\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eLX Series Hub Lineup — Get the Right Size\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLX58\u003c\/strong\u003e — 5\/8\" shaft\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLX78\u003c\/strong\u003e — 7\/8\" shaft (this part)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLX100\u003c\/strong\u003e — 1\" shaft\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLX118\u003c\/strong\u003e — 1-1\/8\" shaft\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLX138\u003c\/strong\u003e — 1-3\/8\" shaft\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhy Buy From OEM Diagnostic Tools?\u003c\/h3\u003e\n\u003cp\u003eWe stock the full Cast Air LX hub series and have been supplying shops with compressor parts since 2016. When a motor hub fails, you need the correct part the same day — not a week later. Free shipping on qualifying orders. If you need help confirming the right hub for your specific Cast Air compressor, call us with the model number.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCall 866-217-0063 for quick answers and help!\u003c\/strong\u003e\u003c\/p\u003e","brand":"Cast Air","offers":[{"title":"Default Title","offer_id":53342571430101,"sku":"LX78","price":35.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0622\/8466\/0949\/files\/CastairReplacementAirCompressorMotorHub_83228c4d-415d-4401-944a-d79a7998e584.png?v=1772652735","url":"https:\/\/aircompressorfactorydirect.com\/products\/castair-replacement-motor-hub-7-8-shaft-lx78","provider":"Air Compressor Factory Direct","version":"1.0","type":"link"}