Self Study Program 476 – Rear axle final drive unit 0BF+0BE– Sports differential

VAG SSP 476. The quattro system remains the best known all-wheel drive concept and is immediately associated with Audi.

Quattro stands for:

• outstanding traction
• superior handling
• greater safety
• emotional appeal and fascination

Thus the quattro drive system is one of the most important unique selling points1) of the Audi brand and requires continuous innovation and advancement to ensure that customers are always offered the best on-road all-wheel drive system. With its superior traction and handling dynamics, the quattro technology is already state of the art.

The transmission of drive torque to all four wheels means that there is more lateral friction potential for roadholding. The vehicle retains its handling stability for longer.

Electronic control systems such as the EDS electronic diff erential lock, the typical Audi suspension settings, the ESP handling control system and selective control of wheel torque enable further improvement of traction characteristics and contribute to the enormous pleasure and exceptional safety off ered by the quattro system.

The sports diff erential off ers a new dimension in handling dynamics due to selective control of power transmission to the rear wheels. As a result the vehicle steers even more directly and responsively through corners and holds its line noticeably longer. Understeer becomes a thing of the past.

The sports differential is aimed at customers who place very high demands on the dynamic handling of their cars and are looking for an out-of-the-ordinary driving experience.

The sports diff erential first appeared in 2009 on the Audi S4. Since then, fans of sports-style handling have been able to order the sports diff erential as an option on all S models and the highest-performance versions of the B8, C7 and D42).

For drivers who prefer sports-style handling the sports diff erential is an attractive option unavailable anywhere else in this combination with the quattro drive system.

Customer benefits of sports differential

• improved direct steering response combined with minimal steering eff ort – more agile handling
• outstanding acceleration capacity in corners
• stabilisation of vehicle under load change reactions
• greater handling stability without loss of responsiveness (inverse function of ESP)
• reduction of understeer when accelerating especially under high-grip conditions
• fast system response times
• zero maintenance

CONTENTS

• Basic physical principles
  • Basic principles of lateral torque distribution
  • Possibilities of the torque overlay differential (sports differential)
• Operation – functions
  • Audi drive select
  • System overview
  • Technical data
  • Final drive cutaway
  • Torque overlay gear (internal gear)
  • Multiplate clutch
  • Power flow and handling dynamics
• Oil systems
  • Overview
  • Oil system junctions in sports differential 0BF
  • Oil system junctions in sports differential 0BE
• Hydraulic control system
  • Hydraulic control unit
  • Overview of components
  • Hydraulic circuit diagram
  • Hydraulic function control settings
• Sensors and actuators
  • Oil pressure and temperature sensor G437/G640
  • Pump for all-wheel-drive system V415
  • Hydraulic pump
  • Clutch valve for all-wheel-drive system N445/N446
  • Pressure limiting valves
• Electrical control system
  • Function diagram – B8 models
  • Network bus topology – B8 models
  • Function diagram – D4 and C7 models
  • Network bus topology – D4 and C7 models
  • All-wheel drive control unit J492
• Service
  • Guided functions
  • Other notes and information
  • Overview of repair operations

The self-study programme describes the fundamentals of the design and function of new vehicle models, new automotive components or new technologies.
The self-study programme is not a Repair Manual! Any fi gures quoted merely serve the purpose of facilitating understanding and relate to the version of data valid at the time the SSP was produced.
It is essential that you refer to the latest technical literature when carrying out maintenance and repair jobs.

Language: English
Format: PDF
Pages: 52

Self Study Program 476 – Rear axle final drive unit 0BF+0BE– Sports differential