Audi 80/Avant (B4)

since 1991-1995 release

Repair and operation of the car

Audi 80/Avant
- Technical specification
   15-inch wheels
   Brake system
   Passive safety
   Full drive
   Distributive Torsen-differential
   Dynamics of the movement at a dry paving
   Instructions on operation for all-wheel drive cars
   Blocking of differential of the back bridge
   Motor compartment
   Regular servicing
   Organization of a workplace
   Lubricant works
   Oil consumption
   Right choice of engine oil
   Replacement of engine oil and oil filter
   Check of level of working liquid of the power steering
   Check of level of oil of a mechanical transmission
   Check of level of oil in the drive of the back bridge
   Control of the ATF level in an automatic transmission
   Check of level of oil in the main transfer of an automatic transmission
   Replacement of ATF
   Greasing of hummock drives, hinges and locks
+ Engines
+ System of production of the fulfilled gases
+ Cooling system
+ Fuel tank and fuel pump
+ Air filter and airintaking channels
+ System of injection
+ Coupling
+ Transmission and transmission
+ Suspension bracket and steering
+ Brake system
+ Anti-blocking system of brakes
+ Wheels and tires
+ Body electrical system
+ System of ignition
+ Lighting
+ Signalling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ body Elements
+ Search of malfunctions
+ Specifications

Distributive Torsen-differential

As it was already told, distributive (or interaxal) the differential is necessary for an equilibration of forces between forward and back bridges. (Differentials of forward and back bridges work irrespective of it).

It is located behind in one block with a transmission.

By the way, the name Torsen happens from Gleason firm, the producer of transmissions where this differential was invented. This name – reduction from the English words Torque Sensing that means approximately "the feeling torque". Thereby it is as if the description of action:

  • This differential transfers to the bridge with the best coupling with the road big driving force.
  • It occurs in such a way that one bridge can transfer by 3,5 times big force, than another.
  • But at equally good covering (under both bridges) there is a uniform distribution of traction force to the forward and back bridge – any preference to one of the leading bridges.

Principle of work

The Torsen-differential is based on the principle of a worm gear and uses its basic principles:

  • The worm gear can be calculated in such a way that it will possess high or low coefficient of blocking.
  • The size of coefficient of blocking depends on an angle of lead of a worm – that is from that, how many is located on a worm of flat or abrupt rounds.
  • Example of a flat worm with high coefficient of blocking is the automobile jack in which the starting handle, influencing on a worm, though raises the car, but the car, despite the weight, can never untwist the starting handle and release a jack.


Thanks to the witty device consisting in general of eight worm wheels and 12 gears in connection with the differential case, a hollow shaft, forward and back leading half shafts the action described in the last section is reached in the best way.