Onan 131-0222 Water Pump Shaft Assembly
The Onan 131-0222 Water Pump Shaft Assembly is the rotating backbone of the pump. It takes the belt or drive load at one end, supports the impeller at the other, and runs through the seal and bearings in between. Any wear or bend in it shows up immediately as seal leakage and bearing noise.
The failure most owners meet is a groove worn into the shaft where the seal lip runs. A new seal placed on a grooved shaft leaks again within hours, which is why a shaft and seal are often replaced together. Check the impeller drive feature for wear at the same time. 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.
Key Features
- Machined to the original Onan shaft dimensions and drive features
- Ground seal track for a reliable shaft seal fit
- Positions the impeller correctly in the pump housing
- Direct replacement, no modification to the pump required
- Supplied to suit rebuild alongside seals and bearings
Applications
- Raw water pump rebuilds on Onan marine generator sets
- Replacing a shaft grooved or pitted at the seal track
- Repairing damage after a seized or locked impeller
- Full wet end and drive end overhaul
Specifications
- Brand: Onan
- Manufacturer Part Number: 131-0222
- Part Type: Shaft Assembly
- 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: 0.4 lb
Frequently Asked Questions
Q: Can a worn shaft be built up and reground?
It is rarely worth the cost on a pump this size, and an undersize shaft will not hold a standard seal.
Q: Should the bearings be replaced with the shaft?
Yes. If the shaft has failed the bearings have usually seen salt water too, and they are the cheap part of the job.
Q: How do I check a shaft for straightness?
Roll it on a flat surface or set it up in vee blocks with a dial gauge. Visible wobble at the impeller end means replace it.
Q: Does the shaft need lubrication on assembly?
Lubricate the seal lip and the seal track before assembly so the lip is not run dry on first start.
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 shaft assembly.
CLRMarine
