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Eaton S-3206 Primary Drive Gear | Endurant HD OEM
Eaton S-3206 Primary Drive Gear (Main Shaft Welded Gear Assembly – Splitter) for Endurant HD transmissions. Direct OEM replacement in input shaft kits (EAHDK-4659, EAHDK-4660, EAHDK-4661). Precision-welded for splitter synchronization. Global shipping & lifetime warranty. Get your quote today!
Product Details
Eaton S-3206 Primary Drive Gear – Endurant HD OEM (Main Shaft Welded Gear Assembly – Splitter)
Factory-direct OEM replacement part for Eaton Cummins Endurant HD automated transmissions. The S-3206 is the official Primary Drive Gear (also called Main Shaft Welded Gear Assembly – Splitter), a precision-welded component integral to the splitter synchronization system. It meshes with the Rail B synchronizer ring and sliding sleeve to enable smooth range splitting and reliable power transfer in high-mileage heavy-duty applications.
Why Choose the Eaton S-3206 Primary Drive Gear?
- Precision-welded OEM assembly – exact factory specification for splitter function
- Critical for Rail B synchronization and smooth automated shifting
- Included in major input shaft kits (EAHDK-4659 ISO, EAHDK-4660 SAE, EAHDK-4661 Detroit)
- Direct replacement during input shaft or main shaft service
- Compatible with Hard Lock bearing upgrades (10004584 input bearing)
- 28 years of OEM-level manufacturing experience at Volgen Power
Technical Specifications
| Parameter | Specification |
|---|---|
| OEM Part Number | S-3206 (also listed as EAHDS-3206 in some catalogs) |
| Description | Gear Assembly, Main Shaft Welded (Splitter) / Primary Drive Gear |
| Function | Meshes with Rail B synchronizer ring (10002550) and sliding sleeve (10001942) for splitter operation |
| Material | High-strength welded steel assembly |
| Weight (approx.) | 7-8 lbs (based on similar welded gears) |
| Included In | Input Shaft Kits: EAHDK-4659 (ISO), EAHDK-4660 (SAE), EAHDK-4661 (Detroit) |
Vehicle & Transmission Compatibility
Designed exclusively for Eaton Endurant HD Series:
| Transmission Models | Application Notes |
|---|---|
| EEO-17F112C / EEO-17F112C-XD | 17-speed Endurant HD |
| EEO-18F112C | 18-speed Endurant HD |
Popular Applications: Freightliner Cascadia, Peterbilt 579/567, Kenworth T680, International LT – paired with Cummins X15, Detroit DD15, PACCAR MX, or CNG engines.
Important Compatibility Note: This S-3206 Primary Drive Gear is a standard component across most Endurant HD input shaft kits (ISO/SAE/Detroit configs). Always verify transmission serial number and input shaft type (e.g., via end stamping or measurement) to ensure an exact match. Pairs with Rail B synchronizer ring (10002550), sliding sleeve (10001942), and input shaft assemblies (S-3205, S-3207, etc.). For Hard Lock upgrades, compatible with input bearing 10004584 and cover kit K-4657.
Installation Highlights
Requires main housing or input shaft access (transmission removal recommended). Replace during input shaft service or when synchronizer wear is present. Press-fit bearings/O-rings as needed, torque to spec, and perform main shaft end-play adjustment (selective washers: 10000555, 10001759, 10001760) if disturbed. Full clutch recalibration via ServiceRanger required. Total service time: 6–10 hours as part of a larger repair. Reference Eaton Endurant HD Service Manual TRSM0950 and Primary Drive Gear Replacement procedure.
Why Buy from Volgen Power?
- 100% genuine OEM specification – direct from the Eaton Cummins supply chain
- Factory direct pricing – up to 40% lower than dealerships
- Lifetime warranty on all transmission components
- Fast global shipping from China + USA warehouse stock
- Trusted by fleets in 70+ countries since 1996
- Full technical support & compatibility verification
Frequently Asked Questions
What is the Eaton S-3206 Primary Drive Gear?
It is the welded main shaft gear assembly (splitter) that interfaces with the Rail B synchronizer system for range splitting in Endurant HD transmissions.
Is S-3206 the same as the Main Drive Gear?
Yes – it is commonly referred to as the Primary Drive Gear or Main Shaft Welded Gear Assembly (Splitter). It meshes with the input shaft’s main drive gear (A-10000902 / EAHDA-10000902).
Is this part compatible with Hard Lock upgrades?
Yes – it is standard in kits using Hard Lock input bearings (10004584) and requires a matching Input Shaft Cover Kit K-4657 when applicable.
Do I need to replace related parts?
Yes – always replace synchronizer ring (10002550), sliding sleeve (10001942), and small parts kit (K-4388) during service for optimal performance.
What is your warranty on this part?
Lifetime warranty against manufacturing defects when installed correctly.
Need input shaft kit compatibility check?
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