Onan 518-0373 Water Pump Snap Ring
The Onan 518-0373 Water Pump Snap Ring locates a component axially inside the pump so it cannot move along the shaft or out of its bore. It is a small part with a large job, because the bearing and seal positions inside the pump depend entirely on it staying seated in its groove.
Retaining rings lose tension when they are overspread during removal, and they corrode in a salt water environment. A ring that no longer springs tight in its groove can jump out under vibration, letting the part it retains move and destroying the pump internals in short order. This part is listed for Onan water pump 131-0257 (casting 170-3172) on MCCK 4.0 and 6.5 kW and MDJE 7.5 kW generator sets. This is the large snap ring in that pump. The small ring is 518-0392.
Key Features
- Sized to the Onan pump groove diameter and thickness
- Positively locates bearings, seals or shaft components
- Correct spring tension for a secure seat in the groove
- Single use part, fitted new at every rebuild
- Inexpensive insurance against internal movement
Applications
- Raw water pump rebuilds on Onan marine generator sets
- Reassembly after bearing or seal replacement
- Replacing rings corroded or sprung during disassembly
- Stocking as a spare with pump service parts
Specifications
- Brand: Onan
- Manufacturer Part Number: 518-0373
- Part Type: Snap Ring
- Fits: Onan water pump 131-0257 (casting 170-3172) on MCCK 4.0 and 6.5 kW and MDJE 7.5 kW generator sets
- Quantity Per Pump: 1
- Condition: New
- Shipping Weight: 0.1 lb
Frequently Asked Questions
Q: Should I keep spares aboard?
They are small and inexpensive, and they are easy to lose or distort during a job, so most owners carry one or two.
Q: Can I reuse the ring I took out?
It is not recommended. Removal spreads it, and a ring that no longer grips the groove can work loose under vibration.
Q: What tools do I need?
A pair of correctly sized retaining ring pliers. Levering one out with a screwdriver bends it and can damage the groove.
Q: Does the ring have a right way round?
Many do. The stamped or chamfered face goes toward the load. Note the orientation of the old ring as it comes out.
Not sure this is the right part? Send us a Picture of the Pump Plate on your pump and the CLR Marine team will confirm the correct snap ring.
CLRMarine
