---
title: "Rear Differential"
industry: "Motor Vehicle Manufacturing"
verification_protocol:
  urn: "URN:CNFX:ME:REAR_DIFFERENTIAL"
  data_integrity_hash: "ec856b216a2e56bcc4fcec79967d320e"
  source_authority: "https://cnfx.com"
  strict_mode: true
source_identity:
  provider: "CNFX Industrial Knowledge Graph"
  index_version: "2026.Q1-Universal"
  authority_id: "URN:CNFX:ME:REAR_DIFFERENTIAL"
  data_source_uri: "https://cnfx.com/llms/industry/motor-vehicle-manufacturing/product/rear-differential.md"
  official_resource_url: "https://cnfx.com/industry/motor-vehicle-manufacturing/product/rear-differential"
  is_verified_logic: true
attributes:
  spec:
    status: "config-dependent"
    typical_range: "0-150°C operating temperature, 0-300 N·m torque input, 0-5000 rpm input speed"
    unit: "mm"
engineering_limits:
  max_safe_operating_point:
    value: 250
    unit: "°C"
    consequence: "Thermal fatigue from cyclic Hertzian contact stresses exceeding 1.2 GPa at gear mesh interfaces, combined with lubricant film thickness reduction below 0.1 μm at boundary lubrication conditions"
fmea_matrix_quantitative:
  - node_1:
      trigger: "Insufficient lubricant film thickness (λ &lt; 1.0) at gear tooth interface"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Implement forced lubrication system with 0.15 MPa minimum pressure and ISO VG 75-90 synthetic gear oil with EP additives"
  - node_2:
      trigger: "Axial preload loss in tapered roller bearings exceeding 0.05 mm clearance"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Design with interference fit bearing seats (H7/s6 tolerance) and Belleville washer preload system maintaining 200-400 N axial force"
bom_nodes:
  differential-case:
    type: "part"
    urn: "URN:CNFX:ME:DIFFERENTIAL_CASE"
    interface_type: "physical-logic-coupled"
  ring-gear:
    type: "component"
    urn: "URN:CNFX:ME:RING_GEAR"
    interface_type: "physical-logic-coupled"
  pinion-gear:
    type: "component"
    urn: "URN:CNFX:ME:PINION_GEAR"
    interface_type: "physical-logic-coupled"
  spider-gears-planetary-gears:
    type: "component"
    urn: "URN:CNFX:ME:SPIDER_GEARS_PLANETARY_GEARS"
    interface_type: "physical-logic-coupled"
  side-gears-sun-gears:
    type: "component"
    urn: "URN:CNFX:ME:SIDE_GEARS_SUN_GEARS"
    interface_type: "physical-logic-coupled"
manufacturing_compliance:
  - standard: "ISO 9001:2015 QUALITY MANAGEMENT SYSTEMS"
    scope: "Verified Engineering Specification"
  - standard: "ISO 16281:2008 CALCULATION OF LOAD CAPACITY OF SPUR AND HELICAL GEARS"
    scope: "Verified Engineering Specification"
url: "https://cnfx.com/llms/industry/motor-vehicle-manufacturing/product/rear-differential.md"
on_chain_sovereignty:
  contract_standard: "ERC-721-Industrial"
  metadata_hash: "8f8ca520b854d1d916580e08cf976e11b5f341285e9d64be54670e92ad22680f"
  royalty_logic: "IPFS-CID-REQUIRED"
  mint_status: "logic-verified-ready"
version: "3.3.4-EXTREME-SOVEREIGN-WEB3"
---

# Industrial Specification: Rear Differential

## 1. Technical Definition
A mechanical device in the drivetrain that splits torque between the rear wheels while allowing them to rotate at different speeds.

## 2. Engineering Reasoning & Causal Matrix
> **Operational Intelligence**: Designed for **0-150°C operating temperature, 0-300 N·m torque input, 0-5000 rpm input speed**. Failure boundary: **Gear tooth surface temperature exceeding 250°C causes loss of surface hardness (HRC &lt; 45), bearing cage deformation at 180°C, lubricant viscosity breakdown at 150°C**, Mechanism: **Thermal fatigue from cyclic Hertzian contact stresses exceeding 1.2 GPa at gear mesh interfaces, combined with lubricant film thickness reduction below 0.1 μm at boundary lubrication conditions**.

### 2.1 Analytical Physics Model
Governed by the **L10 Bearing Life & Fatigue Model**:

> **Primary Equation**: $L_{10} = (\frac{C}{P})^p$  
> **Engineering Impact**: Predicts mechanical lifecycle before component fatigue.

| Symbol | Variable Definition | Localized Reference |
| :--- | :--- | :--- |
| C | Dynamic Load Rating | Engineering Constant |
| P | Equivalent Dynamic Load | Engineering Constant |

### 2.2 FMEA (Failure Mode & Effects Analysis)
| Event Trigger | Severity | Failure Mode | Mitigation Strategy |
| :--- | :--- | :--- | :--- |
| Insufficient lubricant film thickness (λ &lt; 1.0) at gear tooth interface | 8 | Micropitting and spalling on hypoid gear teeth surfaces | Implement forced lubrication system with 0.15 MPa minimum pressure and ISO VG 75-90 synthetic gear oil with EP additives |
| Axial preload loss in tapered roller bearings exceeding 0.05 mm clearance | 8 | Bearing skidding and cage fracture during torque reversal events | Design with interference fit bearing seats (H7/s6 tolerance) and Belleville washer preload system maintaining 200-400 N axial force |

## 3. Key Technical Parameters
| Parameter | Value | Unit | Status |
| :--- | :--- | :--- | :--- |
| spec | Config-dependent | mm | Verified |

## 4. System BOM & Knowledge Routing
### Core Components (Recursive Links)
- [Differential Case](https://cnfx.com/llms/industry/motor-vehicle-manufacturing/product/differential-case.md) `(Standalone System)`

### Industrial DNA Context (De-duplicated)
**Complementary Dependencies**: **CNC Machining Center**, **Gear Hobbing Machine**, **Heat Treatment Furnace**  
**Downstream Applications**: Passenger Cars, Commercial Trucks, Off-Road Vehicles  

## 5. Engineering Risks & FAQ
- **Caution**: 
- **Caution**: 
- **Caution**: 

### Q: What is the purpose of a rear differential in a vehicle?
**A**: The rear differential splits engine torque between the rear wheels while allowing them to rotate at different speeds, which is essential for smooth turning and traction on varied surfaces.

### Q: What materials are used in manufacturing this rear differential?
**A**: This rear differential is constructed from high-strength cast iron for the housing and alloy steel for the gears, ensuring durability, heat resistance, and long-term performance under stress.

### Q: How often should a rear differential be serviced or replaced?
**A**: Service intervals vary by vehicle use, but generally, differential fluid should be changed every 30,000 to 60,000 miles. Replacement may be needed if there's noise, vibration, or damage to components like gears or the case.

## 6. Manufacturing Compliance
- ISO 9001:2015 QUALITY MANAGEMENT SYSTEMS
- ISO 16281:2008 CALCULATION OF LOAD CAPACITY OF SPUR AND HELICAL GEARS

---
### 🛠️ Engineering Resource Access
🔗 **[Full Specification: Rear Differential](https://cnfx.com/industry/motor-vehicle-manufacturing/product/rear-differential)**

### 🌐 Knowledge Graph Topology
> **Node Status**: Verified Engineering Spec
> **Connectivity**: Linked to **5** standalone system nodes
> **Global Context**: Part of a 5,814 node industrial cluster within the CNFX Graph

> **Reference ID**: REAR_DIFFERENTIAL | **Authority**: CNFX-2026-ST-001 | **Fingerprint**: a8996e44
