Camshaft Gear 3946436 | Verified Fitment for Cummins Engine

Cross-Reference Verified — Each 3946436 camshaft gear is validated against Cummins B-series engine serial ranges and Hyundai loader model variants before dispatch, eliminating spline or bore mismatches.

Technical Specifications

Application Suitability

Why the Same Part Number Ships in Multiple Variants

The base number 3946436 covers camshaft gears with different internal bore profiles and tooth counts across engine generations.

A cross-reference table copied between sellers often omits variant distinctions. I once received a returned Camshaft Gear 3946436 from a workshop that had followed a printed catalog listing. The spline tooth count was off by two, and the gear would not mesh with the crankshaft gear on a Cummins ISB build. The machine sat idle while the correct variant was sourced. Errors like this propagate through the aftermarket because one incorrect entry gets duplicated across dozens of listings [NEED_CITE: aftermarket cross-reference accuracy in heavy equipment parts distribution].

Engine Serial Range Determines the Correct Variant

Cummins B-series engines have undergone several internal revisions across production decades. A Camshaft Gear 3946436 for an early 6B5.9 may differ in keyway position from one destined for a QSB5.9 30 CM550 build. Providing the engine serial number allows the technical team to narrow the correct variant from the cross-reference pool, including alternate designations like J946436 (cross-reference only) and K3946436 (cross-reference only), each tied to specific production runs.

Bore Diameter and Tooth Profile Must Match Precisely

The internal bore of this camshaft gear interfaces directly with the camshaft journal. A mismatch of even a fraction of a millimeter causes either a loose fit that hammers under load or a press fit that damages the shaft during installation. The CNC-machined tooth profile must also align with the mating crankshaft gear geometry. On Hyundai HL757-7 loaders operating in high-cycle material handling, any deviation accelerates flank wear and generates timing drift across the valve train.

Decoding Material and Heat Treatment Specifications

The high-strength alloy steel construction provides the core toughness required for continuous gear mesh loading in diesel engines. Heat treatment hardens the tooth flanks to resist pitting and spalling under repeated contact stress, while the core retains enough ductility to absorb shock loads during engine startup. CNC machining ensures the tooth involute profile stays within tolerance, which directly affects how evenly load distributes across each tooth face during operation. In Cummins ISB and QSB platforms, where camshaft timing precision governs fuel injection events, profile accuracy also supports consistent combustion timing [NEED_CITE: gear tooth profile tolerance standards for diesel engine timing drives].

What Happens When Fitment Verification Gets Skipped

A gear that physically bolts on but has the wrong tooth count or bore tolerance creates problems that surface weeks later. Timing drift leads to poor combustion, elevated exhaust temperatures, and eventually valve-to-piston contact in interference engines. On a Hyundai 135D-7 forklift working double shifts in a distribution yard, that kind of failure means pulling the engine for a second teardown. The labor cost of a misfit camshaft gear far exceeds the part cost, and the machine downtime compounds across the fleet schedule [NEED_CITE: cost impact of timing gear failure in industrial diesel engines].

Why Buyers Source This Part Through Our Guangzhou Facility

Our own production lines and qualified sourced supply operate under one warranty and one quality standard, so whether the Camshaft Gear 3946436 comes from our facility or a certified partner, inspection criteria remain identical. Eight product categories mean you can add seals, gaskets, and adjacent timing components to the same order. Minimum order starts at one piece, which matters when a single machine is down. Cross-reference verification covers superseded numbers and alternate designations, confirmed by our technical team before shipment. Sample supply is available so you can verify bore dimensions, tooth count, and fitment on your bench before committing to a bulk order.

Documentation & Verification

• Commercial invoice listing part number 3946436 with cross-reference J946436 and K3946436 noted as reference only
• Fitment sheet mapping your engine serial range to the confirmed camshaft gear variant
• Dimensional inspection record covering bore diameter, tooth count, and keyway position
• Warranty terms document specifying coverage period against manufacturing defects
• Packing photographs showing gear condition and protective wrapping before crate closure
• HS code and customs classification support for international shipment clearance

Fitment Check Before Installation

• Measure the internal bore diameter with a bore gauge and compare against the camshaft journal dimension
• Count the gear teeth and verify against the crankshaft gear tooth count for correct ratio
• Inspect the keyway or spline profile for burrs or machining marks before sliding onto the shaft
• Trial-fit the gear on the camshaft without the timing cover to confirm axial seating depth
• If dimensions do not match, halt installation and contact the supplier with photographs and measurements for exchange

Confirm Your Machine Match Before Ordering

Provide the engine model, serial number, or a photograph of the existing gear and nameplate. The technical team will cross-reference your specific build against the 3946436 variant pool and confirm tooth count, bore size, and keyway configuration within two hours. For Hyundai loader applications, include the machine model and serial range so we can verify the engine-to-drivetrain configuration. Sample units are available for physical fitment checks before you place a production order.

Frequently Asked Questions

Q: How do I confirm Camshaft Gear 3946436 fits my specific Cummins engine or Hyundai loader? A: Send the engine model, serial number, or a clear photograph of the nameplate. Our technical team cross-references your build against variant records covering bore diameter, tooth count, and keyway position. For Hyundai HL757-7 or forklift models, we also verify the engine platform and production run to ensure the correct variant is matched before dispatch.

Q: My old part is marked J946436 or K3946436 — can I use 3946436 as a direct replacement? A: These are cross-reference designations (reference only) linked to the same base gear family but potentially different production variants. We verify whether your specific engine serial range accepts 3946436 as a substitute by checking bore dimensions, tooth profile, and keyway configuration against the original build data before confirming compatibility.

Q: Why does the same base number have different suffix variants, and how do I choose? A: Cummins revised internal components across B-series generations, and suffix variants reflect changes in bore tolerance, keyway geometry, or tooth count for specific engine builds. Send us your engine serial number so we can identify which variant your engine requires, rather than relying on a general cross-reference table that may not distinguish between production runs.

Q: The nameplate on my machine is worn and only the model is readable — how do I get the right part? A: Provide the machine model and, if possible, a photograph of the old gear showing any visible markings or casting numbers. We use the model to narrow the engine platform, then verify the correct Camshaft Gear 3946436 variant through tooth count and bore measurement comparison with known build configurations for that model range.

Q: Can I order a single sample to verify fitment before placing a bulk order? A: Yes, minimum order is one piece. Request a sample to physically check bore diameter, tooth engagement, and axial fit on your camshaft. Once fitment is confirmed on the bench, you can proceed with a bulk order knowing the variant is correct for your engine serial range and machine application.