12V 10T Starter Motor 4996706 – Verified Fitment for Cummins

Verified Cross-Reference — Cummins B and QSB families map to this starter motor across more than twenty engine variants, each confirmed against serial range and mounting pattern before dispatch.

Technical Specifications

Application Suitability

Why the Same Part Number Arrives in Hidden Variants

Superseded numbers and variant-specific pinion configurations mean a matching reference alone does not guarantee fitment.

Buyers holding a worn nameplate often find that the starter motor they ordered matches the book but refuses to seat against the flywheel housing. In Shandong's manufacturing belt, I have pulled starters off B-series engines where the base casting looked identical but the drive gear sat two teeth off — enough to strip the ring gear on the first crank. Cross-reference tables copied between sellers carry these mismatches forward silently, so the 4996706 you receive may bolt on but never engage [NEED_CITE: Cummins B-series starter motor variant identification across engine serial ranges].

The cost is never just the part. It is the machine sitting idle while a replacement ships, the ring gear damage discovered only after forced installation, and the second round of downtime once the correct variant is identified. Starter Motor for Cummins 4B3.9 / QSB6.7 fitment cross reference work requires serial-level verification, not just number matching.

Engine Serial Range and Variant-Level Identification

This starter motor covers the Cummins B-series, ISB, and QSB families — a span that includes naturally aspirated 4B3.9 units through turbocharged QSB6.7 CM2350 builds. Within that range, the mounting flange pattern remains consistent, but the pinion engagement depth and nose cone length shift between early and late production serial blocks. Confirming fitment means matching your engine serial prefix against the verified table rather than trusting a catalog year alone. The Starter Motor for Cummins 4B3.9 / QSB6.7 fitment cross reference database we maintain includes CM-designated variants that many generic listings omit entirely.

Mounting Pattern, Port Position, and Drive Gear Verification

The 10T pinion must mesh cleanly with the flywheel ring gear — wrong tooth count or incorrect helix angle produces grinding on engagement and accelerated wear on both gears. Beyond the pinion, the solenoid terminal orientation and B+ stud position determine whether your existing wiring reaches without modification. Cross-referenced numbers 4280007090, 4280007091, 4280007092, 4380003110, and 5128000980 all map to this unit, but each originated from a different production period or equipment application [NEED_CITE: starter motor cross-reference interchange standards for off-highway diesel engines]. Before committing to a fleet order, request a sample and physically compare the flange bolt circle, pinion standoff distance, and terminal clock position against the removed unit.

Reading the Specification Sheet for Real-World Fitment

The 12V rating places this starter in the standard light-to-mid diesel cranking category, suitable for B-series four-cylinder and six-cylinder Cummins engines up to 8.3 litres displacement. The 10T pinion gear is the critical interface dimension — it must match the ring gear tooth space width and pressure angle on your specific flywheel. Voltage alone tells you the electrical system compatibility, but the mechanical engagement geometry determines whether the starter seats, cranks, and retracts cleanly. New aftermarket condition means fresh brushes, a tested solenoid, and bearings that have not accumulated wear from a previous service life, which matters when cranking torque must reach peak value within the first rotation.

The Cost of Fitment Guesswork on a Down Machine

A starter that bolts on but fails to engage wastes the entire delivery lead time before the mismatch surfaces. Forced installation of an incorrect pinion damages the flywheel ring gear, converting a single-component swap into a rear-engine teardown. On demolition excavators and quarry loaders, that secondary repair extends downtime from hours into days. Even when the part is returned, the freight cost and re-order delay compound against the project schedule [NEED_CITE: equipment downtime cost impact from incorrect aftermarket part fitment].

Why Buyers Source This Starter Here

Our production lines and qualified sourcing partners operate under one warranty and one account, so whether the unit ships from our own facility or a certified partner, the quality commitment holds. Eight component categories sit under the same roof, meaning adjacent items like alternators, belt tensioners, and seal kits consolidate into a single dispatch. Minimum order is one piece — a single emergency starter ships without padding the order. Part identification works from a part number, a machine model, or a photograph of a painted-over nameplate. Cross-reference verification covers superseded and alternate numbers across the full Cummins range. Sample units are available for physical fitment validation before you commit to a bulk purchase, and our technical team confirms compatibility against your engine serial before the order ships.

Documentation & Verification

• Commercial invoice and packing list itemized by engine variant and cross-reference number
• Fitment and cross-reference sheet marking all OEM numbers as reference only
• Dimensional inspection record covering flange bolt circle and pinion standoff
• Warranty terms specifying coverage period and manufacturing defect scope
• Pre-dispatch packing photographs showing terminal orientation and protective wrapping
• HS code and customs documentation support for cross-border shipment

Fitment Check Before Installation

• Compare the 10T pinion tooth profile and helix angle against the removed starter before mounting
• Verify flange bolt circle diameter and bolt hole count match the flywheel housing pattern
• Check solenoid terminal clock position against your existing wiring harness reach
• Confirm pinion engagement depth by measuring nose cone standoff against the old unit
• Hand-rotate the drive gear to verify smooth retraction before applying power
• If any dimension mismatches, halt installation and request cross-reference re-verification

Send Us Your Details for Fitment Confirmation

Provide your Cummins engine model, serial number, or a clear photograph of the existing starter and nameplate. We will cross-reference against the verified fitment table and confirm whether this 4996706 starter matches your specific variant, including any superseded numbers your unit may carry.

Frequently Asked Questions

Q: How do I confirm this starter fits my specific Cummins engine variant? A: Send your engine model and serial number — the CM designation matters because QSB6.7 CM2250 and CM2350 variants differ in pinion engagement depth. We cross-check against our verified table and confirm the flange pattern, pinion tooth count, and terminal position before the order processes.

Q: My old part number is different — is it still a valid cross-reference? A: Numbers like 4280007090 or 5128000980 are superseded or alternate references that map to this starter motor. We verify each against the application range to confirm it covers your engine serial block. Some discontinued numbers carry fitment restrictions we flag before shipping.

Q: I only have the machine model, no readable part number — can you identify it? A: Yes. Send a photograph of the machine nameplate or the engine data tag. We identify the engine family and serial range from the model, then narrow down the correct starter variant by cross-referencing production date and equipment application records.

Q: Can I get a sample to test fit before ordering for the whole fleet? A: Sample units ship under the same warranty terms. We recommend a physical fitment check on one machine — comparing flange dimensions, pinion engagement, and terminal orientation — before releasing the remaining fleet quantity from stock.