Mechanical steering
Before model year 1982 on BMW «518», «520», «520i», «525» mechanical steering was installed with a globoidal cylindrical worm mechanism - a two-ridged roller (up to model year 1978 brand ZF-Gemmer). Since model year 1982, it has only been used on BMWs «518».
The steering drive is three-link, consists of one middle and two side rods, a bipod, a pendulum lever and rotary levers.
Mechanical Steering Specifications
The moment of friction of the bipod shaft from the position of rectilinear movement, kgf cm: 8-12.
Worm shaft friction moment (without gland), kgf cm: 1.5-3.0 («525»: 1.5-2.5).
Gap between the adjusting screw and the bipod shaft, mm: 0-0.05. Steering shaft length, mm: 942 («525»: 923+40mm for steering wheel adjustment).
Steering shaft bearing preload into the flexible coupling flange, mm: 12.5 («525»: 25 mm).
Turning radius of the most distant point, m: 5.25.
Tightening torques of the main threaded connections, kgf·m
- Steering wheel nut: 8.5.
- Nut of a bolt of fastening of an elastic coupling: 2,0-2,3.
- Nut of a bolt of fastening of a flange of an elastic coupling: 2,5-2,8.
- Bipod fastening nut: 12.0-14.0.
- Bolt of fastening of covers of a crankcase of the steering mechanism: 2,2-2,4.
- Adjustment screw locknut: 2.5-3.0.
- Bolt for fastening the crankcase of the steering mechanism to the cross member of the front suspension: 4.5-5.0.
- Nut castellated ball joint of medium thrust: 3.5-4.0.
- Side link ball joint nut: 4.5-6.0.
- Wheel nut: 8.0-9.0.
Power Steering
Steering with a globoidal worm mechanism - a gear sector on circulating balls, with a hydraulic booster was installed in series from the beginning of the model's production «528» and by special order on other models. Since model year 1982, it has been installed as standard on all models of the BMW 5 Series except «518».
The steering drive is three-link, consists of one middle and two side rods, a bipod, a pendulum lever and rotary levers.
Steering characteristics
Steering shaft length, mm: 835+40 («518», «520», «525»: 854).
The total moment of friction of the worm shaft 8 in the position of rectilinear motion, kgf cm: 12.
The moment of friction of the worm shaft when measured in a vertical position, kgf cm: 2-4.
Gap between the adjusting screw and the bipod shaft, mm: 0.05.
Features of the power steering pump
Brand and type: ZF, lamellar.
Direction of rotation: right.
Pump shaft speed, rpm:
- minimum: 500;
- maximum: 6000.
Minimum productivity, l / min / at a pump shaft speed, rpm: 4.5 * / 500.
* 6.8 l/min for «525», «528», «528i» from model year 1978. From model year 1982, pump performance is: 7.0-8.0 liters at 1000 rpm; 5.5-6.5 l at 3000 rpm; 3.0-4.0 l at 6000 rpm.
Adjustable productivity, l/min: 6.0.
Filling capacity of the hydraulic system, cm3: 1200.
Oil used: ATF Dexron.
Drive belt size:
- «528»: 9,5x900 LA;
- other models: 9.5x825 LA DIN 7753.
Tightening torques of the main threaded connections, kgf·m
- Bolt of fastening of an arm of the pump of the hydraulic booster to the engine: 2,2-2, And.
- Screw fittings of pipelines: 4.5-5.0.
- Bolt of fastening of a cover of a worm: 3,4.
- Shaft cover mounting bolts: 3.1.
- Adjustment screw locknut: 3.0.
- Piston adjusting screw lock nut: 0.6.
- Wheel nut: 8.0-9.0.