Spark Plug 4955850 4937472 5473010 – Model-Matched for Cummins

Cross-Reference Verified — thread length, electrode gap, and heat range checked against each Cummins gas engine variant before dispatch.

Technical Specifications

Application Suitability

Why the*mins Gas Engines

A Spark Plug for Cummins ISB5.9G ISC8.3 L9N cross reference 4955850 4937472 5473010 must be matched to the exact CM code, not just the engine family.

Ordering by engine family alone has cost mining crews in northern Chile a full shift of downtime. A maintenance supervisor requested spark plugs by the ISL designation, received plugs with 2mm shorter thread reach, and forced installation — stripping the cylinder head threads and requiring a helicoil repair before the engine could fire. [NEED_CITE: Cummins gas engine spark plug variant identification across CM platforms] Superseded numbers compound the problem: a plate stamped with 4937472 may now require 5473010 depending on the production date break, and generic cross-reference tables rarely note the serial boundary.

Mapping Three Part Numbers to Their Correct Engine Builds

The Spark Plug for Cummins ISB5.9G ISC8.3 L9N cross reference 4955850 4937472 5473010 covers a wide range, but the three numbers are not universally interchangeable. The 4955850 designation appears on earlier ISB5.9G and ISC8.3 builds, while 4937472 shifted into production for C Gas Plus and L Gas Plus platforms. The 5473010 reference entered with the L9N CM2380 and later QSL9 G CM558 variants. Confirming which number fits requires both the engine model and the CM controller code from the ECU label.

Thread Reach, Electrode Gap, and Heat Range Verification

Thread reach is the dimension most likely to cause physical damage during a misfit. A plug that is 2mm short leaves exposed threads in the combustion chamber, creating a hot spot and pre-ignition risk. A plug that is 2mm long can contact the piston crown. Beyond thread length, electrode gap must match the ignition module's output specification — a gap set for an ISC8.3 G CM2180 will not perform correctly in a QSL9 G CM558 running a different coil voltage. [NEED_CITE: gas engine spark plug thread reach and pre-ignition correlation] Nickel-plated shells resist seizure in aluminum heads, but only if the thread form and pitch are verified before installation.

Specification Breakdown for Gas Engine Ignition Demands

Copper core electrodes conduct heat away from the firing tip more effectively than solid alloy alternatives, which matters in turbocharged gas engines where combustion temperatures cycle rapidly under load changes. The nickel-plated shell serves a dual purpose: corrosion resistance during storage and anti-seize behavior during removal after thousands of heat cycles. Heat range selection — determined by the insulator nose length and internal gas volume — must match the engine's compression ratio and fuel map. Installing a plug with too cold a heat range causes fouling under light load; too hot a range causes pre-ignition under full load. [NEED_CITE: spark plug heat range selection for industrial natural gas engines]

The Cost of Installing the Wrong Variant

A Spark Plug for Cummins ISB5.9G ISC8.3 L9N cross reference 4955850 4937472 5473010 that threads in but has the wrong heat range will not fail immediately — it fails after several hundred hours as electrode erosion or carbon fouling degrades combustion. By that point, the engine has been running with incomplete burn, increasing fuel consumption and raising exhaust temperatures enough to damage downstream catalytic components. The misfire may be diagnosed as a coil or injector fault, sending the repair in the wrong direction entirely. [NEED_CITE: misfire diagnosis misdirection from incorrect spark plug heat range]

Why Fitment Verification Happens Before Dispatch Here

XUNPO operates own production lines on selected part categories and sources the remainder from qualified ISO 9001-certified partners, with both streams carrying identical QC and warranty terms — relevant here because spark plug thread tolerances demand consistent machining regardless of source. Part identification accepts engine model, serial number, nameplate photograph, or the worn original plug itself, which matters when a Chilean mine site can only send a photo of a painted-over plate. Cross-reference verification covers superseded and alternate numbers across the 4955850 / 4937472 / 5473010 chain. Sample supply is available for physical fitment confirmation before a fleet-standardization commitment. A technical team reviews CM code and serial break points rather than shipping on part number alone.

Documentation & Verification

• Commercial invoice listing each Spark Plug variant and applicable engine CM code
• Cross-reference sheet mapping 4955850, 4937472, 5473010 with reference-only notation
• Dimensional inspection record covering thread reach, pitch, and electrode gap
• Warranty terms covering manufacturing defects for 3 to 12 months
• Pre-dispatch packing photographs showing shell condition and thread protection
• HS code and customs documentation support for cross-border shipments

Fitment Check Before Installation

• Compare thread reach of new Spark Plug against removed unit using a caliper
• Verify electrode gap matches the engine calibration sticker before installation
• Hand-thread the first three turns to confirm pitch alignment before using a torque wrench
• Check shell seating against the cylinder head — any gap indicates wrong thread length
• If the old plug shows asymmetric electrode wear, investigate ignition coil output before fitting new units

Request a Fitment Verification

Provide the engine model, CM controller code, and serial number — or a photograph of the nameplate and one removed plug — to confirm which of the three cross-reference numbers fits your specific build. For mixed fleets running several Cummins gas variants, send the full engine list so a consolidated compatibility sheet can be prepared before any bulk commitment.

Frequently Asked Questions

Q: How do I confirm which of 4955850, 4937472, or 5473010 fits my specific Cummins engine variant? A: Provide the engine model and CM controller code found on the ECU label. The three numbers map to different production platforms and serial break points — for example, 4955850 applies to earlier ISB5.9G builds while 5473010 covers L9N CM2380 variants. We cross-reference all three against your specific build data before confirming fitment.

Q: My engine nameplate is worn — can I identify the right spark plug from the machine model alone? A: Machine model narrows the range but may not distinguish between CM variants within the same engine family. A photograph of the ECU label, a serial number, or even the removed spark plug itself allows verification. We have confirmed fitment from painted-over nameplates by cross-checking thread dimensions on the returned sample.

Q: Are these three numbers interchangeable, or does each fit a different engine build? A: They are not universally interchangeable. Thread reach, heat range, and electrode gap differ across the platforms each number was released for. A 4937472 may physically thread into an L9N head but deliver the wrong heat range for that combustion profile, causing fouling or pre-ignition over time.

Q: Can I order a sample to test fitment before committing to a bulk purchase? A: Yes. Sample orders are available for physical thread-in verification, which is recommended when standardizing spark plug supply across a fleet with mixed Cummins gas engine variants. Fitment confirmation at sample stage prevents the far higher cost of receiving a bulk shipment that does not seat correctly.

Q: What do I do if the part number I have is no longer listed in current catalogs? A: Send the obsolete number along with the engine model and serial number. Superseded references across the 4955850, 4937472, and 5473010 chain are tracked, and the current applicable number can be identified through cross-reference verification rather than relying on outdated printed catalogs.