| Brand | AcuNova Remanufactured |
| Manufacturer Part Number | 33108090474 / 33108090481 / 33102284171 / 33102284173 |
| Type | Rear Axle Differential (Active M Differential) |
| Gear Ratio | 3.15 : 1 (Standard OEM Ratio) |
| Placement on Vehicle | Rear |
| Fitment | for BMW F10 M5 / F06 M6 Gran Coupé / F12 M6 Convertible / F13 M6 Coupé |
| Engine | S63B44 4.4L Twin Turbo V8 |
| Condition | Refurbished / Bench Tested |
| Warranty | 1 Year |
| Oil Specification | for BMW Differential Oil MSP/A (Part No. 83229407870) |
| Electrical Components | Actuator Motor NOT Included (reuse original) |
| Country/Region of Manufacture | China (AcuNova Engineering Facility) |
| Model | Chassis | Engine | Year | Gear Ratio |
|---|---|---|---|---|
| for BMW M5 | F10 | S63B44 4.4L Twin Turbo V8 | 2011 – 2016 | 3.15 : 1 |
| for BMW M6 Gran Coupé | F06 | S63B44 4.4L Twin Turbo V8 | 2012 – 2018 | 3.15 : 1 |
| for BMW M6 Convertible | F12 | S63B44 4.4L Twin Turbo V8 | 2012 – 2018 | 3.15 : 1 |
| for BMW M6 Coupé | F13 | S63B44 4.4L Twin Turbo V8 | 2012 – 2018 | 3.15 : 1 |
Please verify part number and confirm compatibility by VIN before purchase.
Each OEM differential is fully disassembled, cleaned, and precision-rebuilt by AcuNova engineers following BMW TIS specifications. All wear items are replaced or restored to OEM standard tolerances.
| Step | Process Description |
|---|---|
| 1️⃣ Disassembly & Cleaning | Complete teardown of housing, clutch pack, and gearset. Ultrasonic and chemical cleaning to remove oil carbon and debris. |
| 2️⃣ Visual & Dimensional Inspection | Gear teeth, bearing seats, and clutch drums inspected for micro-cracks or deformation. Non-destructive dye penetrant test applied. |
| 3️⃣ Bearing & Seal Replacement | All bearings (FAG/NTN/SKF) and oil seals (Corteco) replaced to OEM preload and torque specs. |
| 4️⃣ Clutch Pack Restoration | Multi-plate clutch set resurfaced or replaced with new friction discs. Calibrated for correct torque under MSP/A oil specification. |
| 5️⃣ Reassembly & Torque Setup | Gear backlash, bearing preload, and cover torque set using OEM jigs and torque tables per BMW TIS. |
| 6️⃣ Hydraulic Circuit Integrity Check | Internal oil flow passages tested for leakage and pressure retention. Control solenoid ports verified for seal integrity. |
| 7️⃣ Bench Testing | Dynamic rig simulates wheel slip conditions up to 1500 Nm torque. Noise, leak, and torque bias verified. |
| 8️⃣ Final QC & Serialization | Each differential receives a unique serial number and test report. Units sealed and packed with protective oil film before shipment. |
All refurbishment procedures are conducted under ISO9001 quality management and documented for traceability. AcuNova ensures every differential performs to the same operational standard as new OEM parts.
“for BMW M5/M6” is used for fitment reference only. This is a refurbished OEM Active M Differential, not a mechanical LSD or aftermarket modification. Produced by AcuNova under OEM-equivalent standards, not affiliated with BMW AG.