NSK Ball Bearing

Sealed ball bearing NSK 6203-625DDUC3E for pool and spa pump motors. Imperial bore version of 5/8 inch (15.875 mm) of the 6203 bearing — this is the part that allows the motor shaft to turn freely and drive the impeller. A motor that squeaks, whistles, vibrates, or overheats is almost always a sign of a bearing at the end of its life.

Specifications

• Inner diameter (bore): 5/8" — 15.875 mm
• Outer diameter: 40 mm
• Width: 12 mm
• Sealing: double contact rubber seal (DDU, 2RS equivalent) — retains grease, blocks water and dust
• Internal clearance: C3 — increased clearance that absorbs the thermal expansion of a motor running for extended periods
• E suffix: internal geometry with enhanced load capacity
• Dynamic load: ~9.5 kN · Static load: ~4.8 kN
• Construction: chrome steel, stamped steel cage, pre-lubricated for life
• Manufacturer: NSK (Japan)

Compatibility

Used on the majority of pool and spa pump motors with 48Y and 56Y frames and 5/8" shafts: Century motors (formerly A.O. Smith) UST, USQ, Full Rate, and Up Rate series, U.S. Motors motors, and Hayward Super Pump pumps. Also used on spa motors and pressure cleaner booster pumps.

Check before ordering

The 6203 series comes in several bores that look similar to the naked eye: 5/8" (this model), 1/2", and 17 mm. They are not interchangeable. Measure your motor shaft or note the number stamped on the side of the worn bearing before choosing. Some motors use a different bearing at the front and rear.

Replacement tips

• Replace both bearings at the same time. If one has failed, the other has undergone the same number of hours.
• Change the shaft seal at the same time. The vast majority of bearing failures come from water leaking through a worn or poorly installed seal.
• Install with a press, pressing only on the inner ring. Hitting with a hammer or pushing on the outer ring marks the races and destroys the new bearing in a few weeks.