Steering

General Information

1 — rack and pinion steering gear
2 — tie rod
3 — clamp
4 — nut
5 — clamp
6 — boot
7 — nut
8 — bolt
9 — screen
10 — seal ring
11 — gasket
12 — Servotronic unit
13 — bolt

The steering system consists of the steering wheel, steering shaft, rack-and-pinion steering gear and steering linkage. The steering wheel is threaded onto the shaft, which transmits steering movements to the steering gear.

To make parking easier, the vehicle is equipped with power steering. The steering assist ratio depends on engine speed. At high engine speeds the assist ratio decreases; at low engine speeds it increases.

Some models have power steering whose assist ratio depends on vehicle speed (Servotronic system). As a result, the force applied to the steering wheel is reduced when the vehicle is stationary. At high vehicle speeds the steering assist ratio decreases, which provides better road contact and higher steering precision.

The power steering system consists of the oil pump, oil reservoir and oil lines. The oil pump is driven by a V-ribbed belt. The pump draws oil from the reservoir and supplies it under pressure to the steering gear, where the power steering control element is located.

The driver airbag is located in the steering wheel. In a severe frontal collision the control unit ignites a small charge in the airbag inflator. The gases produced inflate the airbag within a few milliseconds. This time is sufficient to cushion the forward movement of the upper body. Within a few seconds the airbag then deflates, as the gases escape through vent holes in the airbag. For safety reasons, all work on the airbag system must be carried out at a BMW service center.

* Always replace self-locking nuts with new ones. Welding and straightening work on steering system components is not permitted. Work on the airbag system must be performed at a service center. Risk of explosion!