528i Aluminum Front Suspension

Suspension Systems
The E39 will use two different version front suspension Systems. An all aluminum carrier with rack and pinion steering will be employed on the 528i while the 540i will use the steel design front carrier introduced on the E38. The additional weight of the 540i requires that the steel front carrier be used.

528i Aluminum Front Suspension

















The design and shape of the aluminum front carrier requires that a tension rod be used in place of the thrust rod used on the steel version front carrier.

The tension rod is also made of aluminum and mounted to the carrier through a hydraulic bushing as on other systems. The rear lower control arm is also made of aluminum and combines with the tension rod to form the double pivot lower mount.

Additional aluminum components on the front suspension include the steering knuckle and outer strut housing/spring pad.

The use of aluminum components for the front axle assembly offer weight saving advantages, including the unsprung weight. A total weight reduction of 21 kg. (46 lbs) was achieved using the aluminum components.

Aluminum Strut Tubes







The aluminum strut assemblies are identical for the left and right sides. When installing replacements special tool 31 2 200 is required. Be certain the correct orientation mark is aligned with the groove to ensure proper installation.

528i Rack And Pinion Steering







Rack and pinion steering is utilized for the first time on the 5 series vehicle. The steering system not only offers weight savings over the recirculating ball type, but also provides quick steering response through its variable ratio.

The rack gear's teeth are profiled so that the steering ratio becomes quicker as the steering wheel is turned away from center This coupled with a variable power assist fine tunes the steering to both highway and city driving.