System Components: Notes
Steering Gear: The steering gear is bolted at 4 points to the front axle carrier. The gear ratio is variable from 47.0 to 59.0 mm rack movement per steering wheel revolution. This keeps the number of total steering wheel revolutions as low as possible when turning to full lock.
With larger dimensioning, the rack and pinion steering system is used in the E65. The thrust piece required for automatic play compensation is lengthened and equipped with a stronger spring. The thrust piece contains integral lubrication pockets where it contacts the rack for longevity and noise reduction.
The gearing is pressed on the rack to increase resistance to stress. The rack is hollowed which saves weight (reduction of 280 g) and allows air equalization between the right and left bellows eliminating the external plastic tube.
Threadless plug "quick couplings" are used at the supply (1) and return (2) connections on the steering gear.
To release the quick coupling, turn the cap to position 2. The connection is then released by pressing with the thumb while at the same time pulling the quick coupling.
Prior to reconnection, the cap must be reset to the locked operating position (1) and should be plugged into the connection only in this position .
Power Steering Pump: Different power steering pumps are used depending on the vehicle equipment. Vehicles without dynamic drive are equipped with a vane type pump and standard oil reservoir.
A tandem pump is used when the vehicle is equipped with dynamic drive. This pump consists of a radial piston pump with a maximum output of 180 bar and a vane pump section with a maximum output of 135 bar. These vehicles are also equipped with large oil reservoir with oil level monitoring.
Steering Column: The upper steering column with crash element can be compressed telescopically by 70 mm when the steering column is subject to load in the event of a crash. This telescopic action is controlled by a crash element made of fiber glass reinforced plastic.
The compression movement begins when the three plastic pins shear under an axial force of approximately 3 kN.
The telescopic adjustment splines inter-slide allowing compression when the crash element is deformed over a defined length (at a force of 3 to 7 kN).