WIX Oil Filter 51344 Cummins Onan Generator (185-5835)

WIX Oil Filter 51344 Cummins Onan Generator (185-5835)

The WIX 51344 is a full-flow spin-on oil filter commonly used as an aftermarket replacement for Cummins Onan oil filter 185-5835. It is designed to remove damaging contaminants from generator engine oil while maintaining dependable lubrication flow during startup and normal operation.

This heavy-duty filter uses enhanced-cellulose media, an M20 1.5 mounting thread, an anti-drainback valve, and an internal bypass valve. Its approximately 4.07-inch body closely matches the original long-format filter used on select Cummins Onan marine diesel generator sets.

Note: WIX lists 51344 as discontinued as of October 2025. Stock on hand may be limited. Any replacement should be matched to the original Onan 185-5835 specification see the cross-reference list below for alternatives.

Key Features

• Direct aftermarket replacement commonly associated with Onan 185-5835
• Full-flow spin-on lubricating oil filter
• Enhanced-cellulose filtration media
• Nominal filtration rating: 21 microns
• Thread size: M20 1.5
• Height: approximately 4.07 in / 103.4 mm
• Outside diameter: approximately 3.24 in / 82.3 mm
• Rated flow range: 911 GPM
• Bypass-valve setting: 811 psi
• Integrated anti-drainback valve
• Burst-pressure rating: approximately 360 psi
• Attached sealing gasket
• WIX Part Number: 51344
• UPC: 765809513440

Generator Compatibility

The Onan 185-5835 oil filter specification is commonly associated with select Cummins Onan marine diesel generator models, including MDKAL, MDKAV, MDKAW Spacesaver, MDKAZ, MDKBG, and certain related MDK-series configurations. Additional application references associate this filter with select HDKAG, HDKAR, and HDKAQ generator sets. Exact compatibility depends on the complete generator model, specification letter, and engine configuration.

Fitment Notice

Confirm the complete Cummins Onan generator model, specification letter, and serial number before ordering. Similar MDK-series generators may use different oil filters depending on production date, engine version, and filter-head arrangement. Do not select a replacement solely because it uses an M20 1.5 thread the filter length, gasket dimensions, bypass pressure, and anti-drainback-valve configuration must also match the generators lubrication system.

When to Replace

Replace the oil filter whenever the generator oil is changed or at the service interval listed in the applicable Cummins Onan maintenance manual. Earlier replacement may be appropriate following extended operation under heavy electrical load, frequent short generator cycles, fuel, coolant or moisture contamination, long periods of seasonal storage, internal engine repairs, or abnormal oil pressure. Replace any filter that is dented, heavily corroded, or leaking.

Installation Notes

Shut down the generator, allow it to cool, and follow the manufacturers lockout and service procedures before beginning work. Remove the old filter and confirm its gasket has not remained on the filter head. Clean the sealing surface, lightly lubricate the new gasket with clean engine oil, and install by hand to the manufacturers tightening specification. After installation: refill with the specified grade and quantity of oil, run the generator and verify normal oil pressure, inspect for leakage, shut down and allow oil to settle, then recheck and correct the oil level. Note that the correct bypass-valve specification is important an improperly matched filter can restrict lubrication during cold starts or when the media becomes loaded.

Cross-Reference Numbers

• Cummins Onan 185-5835 / 0185-5835
• Fleetguard LF3536
• Baldwin B161-S
• Donaldson P550162
• Sierra 23-7842 / 47-237842
• NAPA Gold 1344
• Luber-finer PH2808
• FRAM PH5317

Cross-reference numbers are comparison aids only. Confirm the original filter number and generator application before substituting brands. Given the WIX 51344 discontinuation, the cross-references above may be useful for sourcing an equivalent replacement.

Other WIX Filters

• WIX Oil Filter 51358 Yanmar Marine Diesel
• WIX Oil Filter 51365 Honda Marine, Tohatsu & Yanmar
• WIX Oil Filter 51515 Ford Marine
• WIX Oil Filter 51806
• WIX Oil Filter 51361 Nissan, Infiniti & Kubota

Parts Desk Insights

The important detail with this filter is the bypass-valve setting many M20 1.5 filters will physically thread onto the engine, but that does not make them correct for a Cummins Onan generator. Matching the Onan part number 185-5835, the full generator model, and its specification letter is the safer approach. With WIX 51344 now discontinued, the cross-references above (particularly Fleetguard LF3536 and Baldwin B161-S) are worth investigating as long-term alternatives. Contact us if you need help identifying a suitable replacement.

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