{"product_id":"castair-replacement-motor-sk-hub-1-5-8-shaft-sk158","title":"Castair Replacement Motor SK Hub 1 5\/8\" Shaft SK158","description":"\u003ch2\u003eCastair SK158 — Replacement Motor SK Hub, 1-5\/8\" Shaft\u003c\/h2\u003e\n\n\u003cp\u003eThe Castair SK158 is a replacement SK-series motor hub for motors with a 1-5\/8-inch output shaft used in Cast Air compressor configurations that specify the SK hub style. The SK designation is critical — Cast Air uses two distinct hub series (SK and SD) on different compressor models, and they are not interchangeable. If your compressor uses an SK hub and your motor shaft measures 1-5\/8 inches in diameter, the SK158 is the correct replacement part.\u003c\/p\u003e\n\n\u003cp\u003eOn belt-driven compressors, the motor hub connects the motor's output shaft to the drive sheave and V-belt system that transfers power to the compressor pump. This component takes the full torque load at every startup and throughout operation. Hub failures — cracked bodies, worn bores, stripped keyways — cause vibration, belt misalignment, and eventually a compressor that cannot run correctly. The repair is a direct hub replacement with the correct OEM part.\u003c\/p\u003e\n\n\u003ch3\u003eHow to Confirm You Need the SK158\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHub Series:\u003c\/strong\u003e Check your existing hub for a part number stamp. If it shows SK158, SK158, or simply \"SK\" with a 158 designation, this is your replacement\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eShaft Diameter:\u003c\/strong\u003e Measure the motor output shaft with a caliper. A 1-5\/8-inch shaft measures 1.625 inches in decimal. If your shaft is 1-7\/8 inches (1.875\"), you need the SK178 instead\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIf Unsure:\u003c\/strong\u003e Call us at 866-217-0063 with your compressor model number and we will confirm the correct hub before you order\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSK Series Hub:\u003c\/strong\u003e Designed for Cast Air compressors specifying SK-series motor hubs — distinct mounting interface from SD-series hubs used on other models\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e1-5\/8-Inch Shaft Bore:\u003c\/strong\u003e Machined to fit a 1-5\/8-inch motor output shaft — precision bore ensures concentric running and eliminates shaft slop\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOEM Cast Air Replacement:\u003c\/strong\u003e Manufactured to original Cast Air specifications — same tolerances as the original hub\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBelt-Drive Application:\u003c\/strong\u003e Transmits motor torque to the belt-drive pulley system for compressor pump operation\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDirect Replacement:\u003c\/strong\u003e No machining, modification, or additional hardware required for compatible Cast Air SK-hub applications\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 SK158\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHub Series:\u003c\/strong\u003e SK\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eShaft Diameter:\u003c\/strong\u003e 1-5\/8 inch (1.625\")\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eComponent Type:\u003c\/strong\u003e Replacement motor drive hub\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e Cast Air (Castair)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePrice:\u003c\/strong\u003e $52.36\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eCast Air Motor Hub Lineup — Full Series Reference\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSD138\u003c\/strong\u003e — SD series, 1-3\/8\" shaft ($31.57)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSD158\u003c\/strong\u003e — SD series, 1-5\/8\" shaft ($31.57)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSK158\u003c\/strong\u003e — SK series, 1-5\/8\" shaft ($52.36). This product.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSK178\u003c\/strong\u003e — SK series, 1-7\/8\" shaft ($52.36)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eSD and SK hubs are different series. The shaft diameter alone does not determine which hub you need — both SD158 and SK158 fit a 1-5\/8-inch shaft, but they are different parts designed for different compressor configurations. Confirm your hub series before ordering.\u003c\/p\u003e\n\n\u003ch3\u003eWhen Does a Shop Need the SK158\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eReplace the motor hub when:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eThe existing SK hub is cracked, the bore is worn out of round, or the keyway is damaged\u003c\/li\u003e\n  \u003cli\u003eThe compressor produces vibration at startup or during operation — often a hub that has loosened on the shaft\u003c\/li\u003e\n  \u003cli\u003eBelt alignment problems persist despite correct tension — worn hub bore causes pulley runout\u003c\/li\u003e\n  \u003cli\u003eReplacing a motor where the replacement motor has a 1-5\/8-inch output shaft in an SK-hub application\u003c\/li\u003e\n  \u003cli\u003ePreventive maintenance stocking for Cast Air SK-hub equipment\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhy Buy From Air Compressor Factory Direct?\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\u003cstrong\u003eAuthorized Cast Air dealer since 2016\u003c\/strong\u003e\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFree shipping\u003c\/strong\u003e on qualifying orders\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFree technical support\u003c\/strong\u003e at 866-217-0063 — we can confirm hub series and shaft size before you order\u003c\/li\u003e\n  \u003cli\u003e\u003cstrong\u003eFull manufacturer warranty\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\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":53342602264789,"sku":"SK158","price":96.56,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0622\/8466\/0949\/files\/CastairReplacementAirCompressorMotorHub_86c825b3-3533-47d0-92b1-8745ee407c29.png?v=1772652934","url":"https:\/\/aircompressorfactorydirect.com\/products\/castair-replacement-motor-sk-hub-1-5-8-shaft-sk158","provider":"Air Compressor Factory Direct","version":"1.0","type":"link"}