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

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

Special tools required:
^ 00 2 030
^ 31 5 250
^ 31 5 253
^ 31 5 256

Warning!
Danger to life!
Mount securing fixture for vehicle on lifting platform to prevent the vehicle from slipping off or tilting down.

Necessary preliminary tasks:
^ Mount securing fixture for vehicle on lifting platform
^ Remove rear wheels
^ Tension both coil springs (and leave on vehicle)
^ Remove complete exhaust system and partially detach rear heat insulation
^ Disconnect plug connection on actuating unit (EMF)
^ Unclip lines for pulse generator, brake pad sensor or shock absorber above rear axle carrier from holders
^ Disconnect plug connection at both ride-height sensors





Version with ride-height control:
Deactivate and drain air spring/suspension system

Important!
Do not use any tools to remove the lower section of the air spring (1).

Tilt lower section of air spring (1) by hand towards front/side.

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





Press clutch 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 tray underneath to catch brake fluid.

Release banjo bolts (1), gripping brake hoses (2) at square head in the process.

Disconnect brake hoses (2) and seal off with plugs.





Installation:
Make sure brake hose is laid without tension and with sufficient spacing to adjoining components.
Tightening torque:
Brake line screws/union screws
E70, E71
M10 x 1 14 Nm
M12 x 1 12 Nm
Blue union screw screw connection in steel e.g. brake hose 16 Nm
Blue union screw screw connection in aluminium e.g. hydraulic control unit 17 Nm





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.

Note:
In a profile rail pair two profile rails are connected to each by toothing.

Insert special tools 31 5 256 in telescopic supports of other profile rail pair.





Note:
The jacking points on the left side are shown.

Align special tool 31 5 256 to opening in rear axle carrier.

Align special tools 31 5 253 to cross-member arms on rear axle carrier.





Version with Dynamic Drive:
Remove 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 carrier only until such stage that the rubber mounts can be changed.

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

After installation:
^ Activate and fill air suspension system
^ Bleed braking system