33 31 503 Lowering/Raising Rear Axle Support (Universal Lifter)

33 31 503 Lowering/raising rear axle support (universal lifter)

Special tools required:







WARNING:
Failure to comply with the following instructions may result in the vehicle slipping off the vehicle hoist and critically injuring other persons.
Load the luggage compartment with a minimum of 100 kg before lowering/removing the rear axle support. This prevents the vehicle from tilting or sliding off the vehicle hoist.

When supporting components, make sure that:
- the vehicle can no longer be raised or lowered
- the vehicle does not lift off the locating plates on the vehicle hoist.







IMPORTANT:
Before lowering/removing rear axle support:
Observe safety information for raising the vehicle
In order to avoid damage to vehicle hoist, perform weight compensation on vehicle.







Necessary preliminary tasks:
- Remove rear wheels.
- Tension both coil springs (and leave on vehicle).
- Remove complete exhaust system.
- Disconnect plug connection on actuator unit (EMF).
- Unclip the cable for pulse sensor, brake pad wear sensor or shock absorber from the holders above the rear axle support.
- Disconnect plug connection at both ride height sensors.

Version with self-levelling suspension:
Deactivate and drain air spring/suspension system







IMPORTANT:
Do not use any tools to dismantle the lower section of the air spring (1).
Tilt lower section of air spring (1) by hand towards front/side.

Installation note:
Press lower section of air spring (1) by hand into wheel carrier until it can be seen and heard to snap into place.







Press brake pedal down to floor and secure with pedal support.

NOTE:
The pedal support may only be released when the brake lines are reconnected.
This prevents brake fluid from emerging from the expansion tank and air from entering the system when the brake lines are opened.







Position an oil sump underneath to catch brake fluid.
Release banjo bolts (1), counter supporting brake hoses (2) at square head in the process.
Tightening torque 34 32 1AZ.
Disconnect brake hoses (2) and seal off with seal plugs.

Installation note:
Make sure brake hose is laid without tension and with sufficient distance to adjoining components.







Engage special tool 31 5 250 with a 2nd person helping completely on workshop jack 00 2 030.
Insert special tools 31 5 253 in telescopic supports of a profile rail pair.
Insert special tools 31 5 256 in telescopic supports of other profile rail pair.

NOTE: In a profile rail pair, two profile rails are connected to one another by gearing.







The jacking points on the left side are shown.

Align special tool31 5 256 to opening in rear axle support.
Align special tool 31 5 253 to cross member arms on rear axle support.
Support rear axle support by operating workshop jack 00 2 030.

IMPORTANT:
The centre of gravity of the rear axle must be positioned centrally over the workshop jack.
Lash rear axle support with tensioning strap 33 5 206 to special tool31 5 250.







Version with ARS:
Remove right underbody panelling (rear section).

IMPORTANT: Pay attention to control lines (2) when lowering and raising. Hydraulic lines must not be kinked/tensioned/bent.

1 = Banjo bolts







IMPORTANT: Lower rear axle support only as far as the point at which the rubber mounts can be changed.

Remove front and rear compression struts and carefully lower rear axle support approx. 50 mm.







After installation:
- Activate and fill air spring system
- Bleed brake system.