Self Study Program 29 – SKODA OCTAVIA 4 x 4
VAG SSP 29. With the OCTAVIA 4 x 4, SKODA is enlarging its production range with a vehicle offering the most modern permanent all-wheel drive technology.
Classical all-wheel drive concepts – still found today in a large number of off-road vehicles -in many cases make use of a rigid connection which is engaged by means of a handshift.
A new technical feature for permanent allwheel drive with an additional connection at the rigid through-drive to the rear, operated independently of the driver, was the viscous coupling, as fitted for example to the VW syncro.
This was in the position only to detect wheel slip, but not the cause of it. To ensure reliable braking in such cases, both axles had to be decoupled by means of a freewheel. When reversing, the axles were again connected by means of a lock.
A significant advance in modern all-wheel technology has been achieved with the development of the Haldex coupling. The Haldex coupling can be controlled.
A processor analyses additional information during the control cycle. It is no longer the wheel slip alone which is decisive for the distribution of the tractive forces, but also the dynamic state of the vehicle.
The processor accesses the ABS wheel speed sensors and the engine management system (accelerator pedal signal) through the CANBUS.
These data provide the processor with the information which is required regarding vehicle speed, cornering, deceleration or acceleration, and enables it to react optimally to the particular situation.
Advantages of the Haldex coupling:
- Permanent all-wheel drive with electronically controlled multi-plate coupling
- Front-wheel drive characteristics
- Rapid response (power transmission)
- Instant decoupling of both axles
- No stresses in the drive train when parking and manoeuvring
- No restrictions when towing vehicle with front wheels raised
- Can be fully combined with wheel slip control systems such as ABS, EDL, TCS, EBD and ESP
- Possibility of simple test of brakes and performance on roller dynamometer
- All-wheel Drive
- Manual Gearbox
- Rear Final Drive
- Cardan Shaft
- Modifications to 4×4 Vehicle
- Rear axle
- Fuel tank
- Vehicle floor
- Exhaust system
- Haldex Coupling
- System description
- Mechanical components
- Multi-plate coupling
- Hydraulic System
- System Overview
- Control Unit
- Self Diagnosis
- Function Diagram
- Driving Situations
- Test Your Knowledge
You will find notes on inspection and maintenance, setting and repair instructions in the Workshop Manual.