E39 Sportwagon And X5 Rear Suspension
With the introduction of the E39 Sportwagon and the E53 X5, the rear suspension system has been modified to accommodate the increased cargo capacity. The rear suspension is also modified to allow for the optional EHC system. The X5 and Sportwagon rear suspensions differ from the standard E38 and E39. The springs are now located on the perches that are part of the wheel carrier assembly. The E39 and E53 rear suspensions are also slightly different from one another, the E39 upper shock mounts are part of the subframe assembly. The E53 upper shock mounts are still located in the body.
Both the E39 and E53 are available with optional EHC, this means that the rear springs will either be coils springs or "air springs".
The E39 rear suspension also uses special "hydro mounts". This modification is necessary due to the fact that the upper shock mounts are on the subframe. The "hydro mounts" are used to isolate the subframe to suppress road noise and vibrations from being transmitted to the body.