Cummins 5.9L 6BT-Compatible Valve Cover Gasket Set – Model-Matched

Verified Cross-Reference — Alternate and superseded numbers mapped to exact engine serial variants before shipment.

Technical Specifications

Application Suitability

Why the Same Part Number Ships in Four Variants

One gasket profile does not cover every engine serial range under the same base number.

A valve cover gasket set referenced as 3902666 spans multiple Cummins engine generations, but the sealing bead path, bolt hole spacing, and port cutouts shift between early 6BT castings and later ISB CM850 heads. Ordering from a catalog page alone, without checking the engine serial, regularly results in a gasket that physically fits the cover but leaves one or more sealing channels misaligned. I have seen this exact mismatch on a 5.9L 6BT pulled from a Hyundai R210LC-7 — the old manual listed a single number, but the actual valve cover had been updated to a later casting during a previous overhaul. [NEED_CITE: Cummins engine serial variant identification for sealing components]

This Valve Cover Gasket Set for Cummins 6BT / cross reference fitment requires serial-level confirmation. The reference numbers 3910824 and 3930906 are superseded or alternate identifiers that map to specific production runs, not interchangeable substitutes across all builds.

Mapping Serial Variants to the Correct Gasket Profile

The Cummins 5.9L family includes B3.9, B5.9, ISB, QSB, and ISC designations, each carrying distinct cylinder head castings. A Valve Cover Gasket Set for Cummins 6BT / cross reference fitment must match the exact head profile — the number of integrated oil passages, the position of the crankcase ventilation port, and the rocker tower clearance all affect which gasket variant seals correctly. We cross-check your engine serial against the casting record to confirm the bead path before cutting or dispatching any set.

Cross-Reference Chains and Superseded Numbers

Reference number 3902666 appears alongside 3910824, 3930906, J902666, and 2853071 across different parts databases. These are not duplicates — each represents a production-period identifier or a manufacturer-internal code that was later consolidated. Our cross-reference table traces each number to its applicable engine serial range and casting variant. [NEED_CITE: aftermarket cross-reference verification standards for engine sealing components] When your nameplate shows a superseded number, we map it forward to confirm whether 3902666 is the valid current replacement or whether a different profile is needed for your specific build.

Sealing Bead Profile and Dimensional Verification

The silicone rubber sealing element with steel core reinforcement maintains dimensional stability at sustained temperatures up to 180°C / 356°F. The ±0.05mm tolerance ensures the gasket seats into the valve cover groove without lateral play, which is critical on high-vibration diesel applications. SAE J429 grade 8 hardware is specified for the retaining fasteners — using lower-grade bolts risks uneven clamping pressure and localized gasket extrusion under thermal cycling. These specifications directly influence whether the gasket maintains seal integrity through thousands of heat-up and cool-down cycles typical in excavator and loader duty.

The Cost of Installing the Wrong Variant

A gasket that fits the bolt pattern but mismatches the sealing channel creates a slow oil weep that may not appear until the engine has run for several hours under load. By that point, the machine is back on site, and diagnosing the leak requires pulling the entire valve cover again — a second teardown, a second gasket, and lost production hours that far exceed the part cost. On fleet machines running tight shift schedules, this Valve Cover Gasket Set for Cummins 6BT / cross reference fitment error cascades into delayed maintenance windows for other scheduled services. [NEED_CITE: cost impact of misidentified sealing components on equipment uptime]

Procurement Based on Verified Fitment

Our production lines and qualified sourced supply operate under a single warranty account, so whether your Valve Cover Gasket Set ships from our own facility or a certified partner, the QC terms are identical. We identify parts from a part number, a machine model, a photograph of the nameplate, or even a worn casting — whichever reference point you have available. Cross-reference verification covers superseded and alternate numbers to prevent catalog-copy errors. A sample unit can be dispatched for physical trial fitment on your machine before you commit to a bulk order. The technical team confirms compatibility and grade against your specific engine serial, not just the model family.

Documentation & Verification

• Commercial invoice and packing list referencing verified part numbers and engine serial ranges
• Cross-reference sheet mapping 3910824, 3930906, and alternate numbers to applicable variants (reference only)
• Dimensional inspection record confirming bead profile, port cutout positions, and bolt hole spacing
• Warranty terms covering 3–12 months against manufacturing defects
• Packing photographs documenting gasket condition and protective packaging before dispatch
• HS code and customs documentation support for international aftermarket shipments

Fitment Check Before Installation

• Compare the new gasket bead path against the old gasket or valve cover groove before removing protective film
• Verify crankcase ventilation port cutout aligns with the cylinder head breather passage
• Confirm all retaining bolt holes match the cover pattern — hole count varies across 6BT casting generations
• Check SAE J429 grade 8 fasteners for thread condition; replace any showing stretch or corrosion
• Torque fasteners in the manufacturer-specified sequence to prevent uneven clamping and gasket extrusion
• If the gasket does not seat flush in the groove, stop — contact us with photos for variant verification

Inquiry Guidance

Send your engine serial number, machine model, or a photograph of the existing valve cover and nameplate. We will confirm which gasket variant matches your specific casting and provide the verified cross-reference chain. For fleet orders covering multiple engine families, include each unit's serial range so we can consolidate the correct profiles into one shipment.

Frequently Asked Questions

Q: How do I confirm this gasket fits my specific engine serial? A: Provide the full engine serial number from the nameplate or data tag. We cross-reference it against the cylinder head casting record to verify the sealing bead profile, port positions, and bolt pattern match the gasket variant we dispatch. If the nameplate is unreadable, a photograph of the valve cover casting number also allows identification.

Q: My old part number is different — is it superseded by 3902666? A: Numbers like 3910824 and 3930906 are alternate or superseded references that may map to 3902666, but only for specific engine serial ranges. We verify the supersession chain against your build record to confirm whether 3902666 is the correct current replacement or if a different profile applies to your engine variant.

Q: Why are there multiple reference numbers for the same gasket set? A: Different reference numbers reflect production-period identifiers, manufacturer-internal codes, or regional catalog variations that were later consolidated. Each number maps to a defined serial range or casting variant. Our cross-reference sheet traces these identifiers so you can confirm which one matches your machine.

Q: I only have a machine model, no readable part number — can you identify it? A: Yes. Provide the machine model (e.g., Hyundai R210LC-7) and, if possible, the engine serial or a photo of the valve cover. We use the machine build record to trace the original engine configuration and confirm the correct gasket profile, even when the original nameplate is worn or painted over.

Q: Can I order a sample first to check fitment before bulk? A: A sample Valve Cover Gasket Set for Cummins 6BT / cross reference fitment can be dispatched for physical trial installation on your machine. This lets you verify groove seating, port alignment, and bolt pattern match before committing to a fleet-quantity order, eliminating the risk of bulk misidentification.