The Castair Replacement Motor Hub with 1-1/8" Shaft (LX118) is the correct motor hub for Cast Air compressor assemblies where the electric motor uses a 1-1/8" output shaft. Shaft diameter is the determining spec here — this hub is machined to fit a 1-1/8" shaft bore and won't interchange with other sizes in the LX series. If your motor shaft measures 1-1/8" (1.125") with calipers, LX118 is your part.
What the Motor Hub Does
The motor hub transfers rotational power from the electric motor's output shaft to the compressor pump's drive assembly — typically through a belt sheave or direct coupling arrangement. A worn, cracked, or loose hub causes misalignment between the motor and pump, leading to vibration, accelerated bearing wear, and belt problems. In worst cases, a failed hub can damage the motor shaft itself. Replacing the hub at the first sign of wear is considerably cheaper than a motor or pump rebuild.
Key Features
- 1-1/8" Shaft Bore: Machined to fit motors with a 1.125" diameter output shaft — measure before ordering
- Cast Air OEM Part: Built to Cast Air's specifications for a correct, no-modification fit
- Precision Bore Tolerance: Maintains concentricity between motor shaft and pump drive for smooth, vibration-free operation
- Direct Replacement: Drops in to replace the original hub on compatible Cast Air units
Technical Specifications
- Part Number: LX118
- Shaft Diameter: 1-1/8" (1.125")
- Component Type: Replacement Motor Hub
- Manufacturer: Cast Air
- Price: $19.25
Note: Manufacturer's product page was unavailable at time of writing. Confirm compatibility with your Cast Air model number before ordering.
When You Need This Part
- Hub is visibly cracked, scored, or has developed play on the shaft
- Compressor is vibrating or producing more noise than normal at startup
- Belt tension is correct but the belt continues to slip or throw off
- Replacing the electric motor and need a hub matched to the new motor's shaft diameter
- Performing scheduled maintenance on a high-hour Cast Air compressor
LX Series Hub Sizes — Order the Right One
Cast Air's LX series motor hubs cover the shaft sizes used across their product line. Measure your motor shaft before ordering:
- LX58 — 5/8" shaft
- LX78 — 7/8" shaft
- LX100 — 1" shaft
- LX118 — 1-1/8" shaft (this part)
- LX138 — 1-3/8" shaft
Why Buy From OEM Diagnostic Tools?
We carry the complete Cast Air LX motor hub series so you can get the right part without hunting across multiple suppliers. We've been serving shops and industrial buyers since 2016 with genuine replacement parts. Free shipping on qualifying orders. If you need help confirming which hub fits your specific compressor, call us with the model number.
Call 866-217-0063 for quick answers and help!
