---
title: "Differential Case"
industry: "Motor Vehicle Manufacturing"
verification_protocol:
  urn: "URN:CNFX:ME:DIFFERENTIAL_CASE"
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  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:DIFFERENTIAL_CASE"
  data_source_uri: "https://cnfx.com/llms/industry/motor-vehicle-manufacturing/product/differential-case.md"
  official_resource_url: "https://cnfx.com/industry/motor-vehicle-manufacturing/product/differential-case"
  is_verified_logic: true
attributes:
  spec:
    status: "config-dependent"
    typical_range: "0-150°C temperature, 0-3000 rpm rotational speed, 0-500 N·m torque"
    unit: "mm"
engineering_limits:
  max_safe_operating_point:
    value: 350
    unit: "MPa"
    consequence: "High-cycle fatigue from cyclic torsional loading exceeding S-N curve endurance limit, thermal expansion mismatch between aluminum housing (23.1×10^-6/°C) and steel components (11.8×10^-6/°C) causing stress concentration"
fmea_matrix_quantitative:
  - node_1:
      trigger: "Insufficient lubrication causing boundary lubrication regime with coefficient of friction &gt;0.15"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Forced lubrication system with 2.5 bar minimum pressure and 80 μm filtration"
  - node_2:
      trigger: "Bolt preload relaxation below 70% of initial 120 N·m torque due to vibration-induced loosening"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Nord-Lock washers with 30° wedge angle maintaining clamp load through vibration to 50 g RMS"
bom_nodes:
  bearing-journals:
    type: "component"
    urn: "URN:CNFX:ME:BEARING_JOURNALS"
    interface_type: "physical-logic-coupled"
  ring-gear-flange:
    type: "component"
    urn: "URN:CNFX:ME:RING_GEAR_FLANGE"
    interface_type: "physical-logic-coupled"
  axle-shaft-openings:
    type: "component"
    urn: "URN:CNFX:ME:AXLE_SHAFT_OPENINGS"
    interface_type: "physical-logic-coupled"
  fillerdrain-plug-bosses:
    type: "component"
    urn: "URN:CNFX:ME:FILLERDRAIN_PLUG_BOSSES"
    interface_type: "physical-logic-coupled"
manufacturing_compliance:
  - standard: "ISO 9001:2015 QUALITY MANAGEMENT SYSTEMS"
    scope: "Verified Engineering Specification"
url: "https://cnfx.com/llms/industry/motor-vehicle-manufacturing/product/differential-case.md"
on_chain_sovereignty:
  contract_standard: "ERC-721-Industrial"
  metadata_hash: "3a4aea117aed627b7b7a41fa2add74a0e125b1fca2b2330be53211b21d74f044"
  royalty_logic: "IPFS-CID-REQUIRED"
  mint_status: "logic-verified-ready"
version: "3.3.4-EXTREME-SOVEREIGN-WEB3"
---

# Industrial Specification: Differential Case

## 1. Technical Definition
The housing that encloses and protects the differential gears and components within a front differential assembly.

## 2. Engineering Reasoning & Causal Matrix
> **Operational Intelligence**: Designed for **0-150°C temperature, 0-3000 rpm rotational speed, 0-500 N·m torque**. Failure boundary: **Material yield strength exceeded at 350 MPa stress, fatigue failure at 10^7 cycles at 250 MPa alternating stress, thermal distortion beyond 0.5 mm at 200°C**, Mechanism: **High-cycle fatigue from cyclic torsional loading exceeding S-N curve endurance limit, thermal expansion mismatch between aluminum housing (23.1×10^-6/°C) and steel components (11.8×10^-6/°C) causing stress concentration**.

### 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 lubrication causing boundary lubrication regime with coefficient of friction &gt;0.15 | 8 | Scoring and adhesive wear on gear contact surfaces leading to 0.1 mm material loss | Forced lubrication system with 2.5 bar minimum pressure and 80 μm filtration |
| Bolt preload relaxation below 70% of initial 120 N·m torque due to vibration-induced loosening | 8 | Housing flange separation creating 0.2 mm gap allowing lubricant leakage at 0.5 L/hour | Nord-Lock washers with 30° wedge angle maintaining clamp load through vibration to 50 g RMS |

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

## 4. System BOM & Knowledge Routing
### Core Components (Recursive Links)

### Industrial DNA Context (De-duplicated)
**Complementary Dependencies**: **CNC Machining Center**, **Coordinate Measuring Machine (CMM)**, **Industrial Parts Washer**  
**Downstream Applications**: Front Differential Assembly, All-Wheel Drive System, Four-Wheel Drive Vehicle  

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

### Q: What materials are commonly used for differential cases in motor vehicle manufacturing?
**A**: Differential cases are typically manufactured from cast iron for durability, aluminum alloy for weight reduction, or forged steel for high-strength applications in demanding vehicle environments.

### Q: What are the key components included in a differential case BOM?
**A**: A standard differential case bill of materials includes axle shaft openings, bearing journals, filler/drain plug bosses, and a ring gear flange to accommodate the complete differential assembly.

### Q: What is the primary function of a differential case in a vehicle?
**A**: The differential case serves as the protective housing that encloses and safeguards the differential gears and components within a front differential assembly, ensuring proper power distribution to the wheels.

## 6. Manufacturing Compliance
- ISO 9001:2015 QUALITY MANAGEMENT SYSTEMS

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

### 🌐 Knowledge Graph Topology
> **Node Status**: Verified Engineering Spec
> **Connectivity**: Linked to **4** standalone system nodes
> **Global Context**: Part of a 5,814 node industrial cluster within the CNFX Graph

> **Reference ID**: DIFFERENTIAL_CASE | **Authority**: CNFX-2026-ST-001 | **Fingerprint**: 4f75d8f6
