Steering Specifications (BMW 5 Series E12)

Mechanical steering

Up to model year 1982 on BMW "518", "520", "520i", "525" mechanical steering with a globoid cylindrical worm - double-ridge roller mechanism was installed (up to 1978 model year of the ZF-Gemmer brand). From the 1982 model year it was used only on the BMW "518".

The steering gear is three-link and consists of one middle and two side rods, a steering knuckle, a pendulum lever and pivot levers.

Mechanical steering characteristics

Friction moment of the bipod shaft from the position of rectilinear motion, kgf·cm: 8-12.

Friction moment of the worm shaft (without seal), kgf·cm: 1.5-3.0 ("525": 1.5-2.5).

Clearance between the adjusting screw and the steering knuckle shaft, mm: 0-0.05. Steering shaft length, mm: 942 ("525": 923+40 mm for adjusting the steering wheel position).



Preload of the steering shaft support in the elastic coupling flange, mm: 12.5 ("525": 25 mm).

Turning radius of the most distant point, m: 5.25.

Tightening torques of main threaded connections, kgf·m

• Steering wheel mounting nut: 8.5.
• Elastic coupling mounting bolt nut: 2.0-2.3.
• Nut of the bolt for fastening the flange of the elastic coupling: 2.5-2.8.
• Bipod mounting nut: 12.0-14.0.
• Steering gear housing cover mounting bolt: 2.2-2.4.
• Adjusting screw lock nut: 2.5-3.0.
• Bolt for fastening the steering gear housing to the front suspension crossmember: 4.5-5.0.
• Ball joint crown nut of medium thrust: 3.5-4.0.
• Lateral tie rod ball joint nut: 4.5-6.0.
• Wheel mounting nut: 8.0-9.0.

Power steering

Steering with a globoid worm-geared sector mechanism on circulating balls, with hydraulic booster was installed as standard from the beginning of the production of the model "528" and by special order on other models. From the 1982 model year, it was installed as standard on all BMW 5-series models, except for the "518".

The steering gear is three-link and consists of one middle and two side rods, a steering knuckle, a pendulum lever and pivot levers.

Steering characteristics

Steering shaft length, mm: 835+40 ("518", "520", "525": 854).



Total friction moment of the worm shaft in the position of rectilinear motion, kgf·cm: 12.

Friction moment of the worm shaft when measured in a vertical position, kgf·cm: 2-4.

Clearance between the adjusting screw and the bipod shaft, mm: 0.05.

Power steering pump characteristics

Brand and type: ZF, plate.

Direction of rotation: right.

Pump shaft speed, rpm:

• minimum: 500;
• maximum: 6000.

Minimum performance, l/min/at pump shaft speed, rpm: 4.5*/500.

* 6.8 l/min for "525", "528", "528i" since 1978 model year. Since 1982 model year, the pump capacity is: 7.0-8.0 l at 1000 rpm; 5.5-6.5l at 3000 rpm; 3.0-4.0 l at 6000 rpm.

Adjustable performance, l/min: 6.0.

Hydraulic system filling capacity, cm³: 1200.

Oil used: ATF Dexron.

Drive Belt Size:

• "528": 9,5x900 LA;
• other models: 9.5x825 LA DIN 7753.

Tightening torques of main threaded connections, kgf·m

• Bolt for fastening the power steering pump bracket to the engine: 2.2-2.A.
• Screw-in pipe fittings: 4.5-5.0.
• Worm cover mounting bolt: 3.4.
• Shaft cover mounting bolts: 3.1.
• Adjusting screw lock nut: 3.0.
• Piston adjusting screw lock nut: 0.6.
• Wheel mounting nut: 8.0-9.0.