Cummins Onan Genuine Oil Filter – 185-7444
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Cummins Onan Genuine Oil Filter – 185-7444
The Cummins Onan 185-7444 is a genuine spin-on engine oil filter designed for select Onan Quiet Diesel and marine generator sets. Its full-flow construction removes damaging contaminants from circulating engine oil while maintaining the lubrication needed to protect bearings and other internal components.
The filter incorporates a bypass valve that allows oil to continue circulating during cold starts or if the filter becomes excessively restricted — an important part of the Onan lubrication-system specification that helps prevent oil starvation when operating conditions temporarily limit flow through the filter media.
Key Features
- Genuine Cummins Onan replacement oil filter
- Full-flow spin-on design
- Built-in filter bypass valve
- Engineered for select Onan Quiet Diesel generators
- Thread size: M20 × 1.5
- Height: approximately 67 mm / 2.64 in
- Outside diameter: approximately 68.5 mm / 2.70 in
- Compact design for generator installations with limited clearance
- Onan Part Number: 185-7444 (also formatted as 0185-7444 and 1857444)
Generator Compatibility
The Onan 185-7444 oil filter is principally associated with select Cummins Onan Quiet Diesel and marine generator models, including MDKBH, MDKBJ, MDKBW, and select related Onan QD generator configurations. Application references may also associate this filter with certain MDKAU installations. Exact compatibility depends on the complete generator model, specification letter, serial number, and installed engine configuration.
Fitment Notice
Confirm the complete generator model, specification letter, and serial number from the Onan nameplate before ordering. Similar-looking MDK-series generators may use different oil filters depending on the engine version and production range. Do not select a replacement solely because it has an M20 × 1.5 thread — filter height, gasket dimensions, bypass-valve specification, and installation clearance must also match the generator’s lubrication system.
When to Replace
Replace the oil filter whenever the generator oil is changed or at the maintenance interval specified in the applicable Cummins Onan operator’s manual. Earlier replacement may be appropriate following extended operation under heavy electrical load, frequent short generator cycles, fuel, coolant, water or debris contamination, long periods of seasonal storage, internal engine repairs, or abnormal oil-pressure conditions. Replace the filter immediately if its housing is dented, heavily corroded, or leaking.
Installation Notes
Shut down the generator, allow the engine to cool, and follow the manufacturer’s service and lockout procedures before beginning work. Remove the old filter and confirm its sealing gasket has not remained on the filter head. Clean the mounting surface, lightly lubricate the replacement gasket with clean engine oil, and install by hand to the Cummins Onan tightening specification. After installation: refill with the specified oil, run the generator and confirm normal oil pressure, inspect for leakage, shut down and allow oil to settle, then recheck and correct the oil level.
Cross-Reference Numbers
- Cummins Onan 185-7444 / 0185-7444
- Fleetguard LF3925
- Kubota HH150-32430 / HH1J0-32430
- Sierra 47-237804
- WIX WL7200
- K&N HP-1008 / SO-1008
Cummins Onan service packages may contain an Onan-, Fleetguard-, or Kubota-labelled filter carrying the corresponding factory specification. Cross-reference numbers should still be confirmed against the complete generator model and serial number before installation.
Related Products
- WIX Oil Filter 51344 – Cummins Onan 185-5835 – aftermarket alternative for a related Onan generator application
Parts Desk Insights
The bypass valve is the detail that matters with this filter. Many compact M20 × 1.5 filters will physically thread onto the engine, but that does not mean their internal valve settings are correct for the Onan generator. Matching 185-7444 and the complete generator nameplate is the safer approach. Note that Cummins Onan service kits for these generators may include a Fleetguard- or Kubota-branded filter carrying the same specification — this is normal and does not indicate an incorrect part.
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In-stock and OEM parts: ship same or next business day.
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Special-order items: timeline confirmed after order.
Returns & warranty
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