31 11 506 Lowering/Raising Front Axle Support
31 11 506 Lowering/raising front axle support (universal lifter)
Special tools required:
WARNING:
Danger of injury.
Failure to comply with the following instructions may result in the vehicle slipping off the lifting platform and critically injuring other persons.
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 front axle support:
Observe safety information for raising the vehicle
In order to avoid damage to vehicle hoist, perform weight compensation on vehicle.
Load spring strut domes with sand bags.
WARNING:
Secure engine in installation position with special tool to prevent it from falling down.
Before lowering the front axle support, it is essential that the steering shaft on the steering box is unfastened.
If this is not carried out, the bulkhead steering shaft bearing will be damaged.
IMPORTANT: N57: Risk of shorting the starter motor.
Necessary preliminary tasks:
- Secure engine in installation position.
- Release steering shaft on steering gear.
- Remove front wheels.
IMPORTANT: Use special tool to avoid preliminary damage to ball joint in upper wishbone and the associated necessary removal of swivel bearing.
Press plug on left and right out of spring strut dome.
Secure swivel bearing (1) on left and right with special tool 31 4 170 in installation position.
Remove underbody protection at front and rear.
Remove steering box cover at top left and right.
Remove reinforcement plate.
Partially detach front left and right wheel arch covers (rear section) at rear area.
Remove lower wishbone from spring strut holder.
Version with active steering:
Disconnect plug connection (1) and unclip line (2) from front axle support.
IMPORTANT:
To avoid the need for axle/wheel alignment, mark position of steering box (1) to front axle support (2).
To do so, draw a wide white stripe on the rear bolting points (left and right) and apply a thin black mark (3) to this stripe.
Release nuts and remove screws (1) towards bottom.
Tightening torque 32 00 1AZ.
Tie up hydraulic steering gear (2).
Installation note:
When installing, make sure that the steering box is re-aligned to the marks applied to the front axle support prior to removal.
Replace screws and nuts.
Engage special tool 31 5 250 with a 2nd person helping completely on workshop jack 00 2 030.
Insert special tools 31 5 255 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 tools 31 5 255 and 31 5 256 to front axle support.
Support front axle support by operating workshop jack 00 2 030.
IMPORTANT: The centre of gravity of the front axle must lie in the middle above the workshop jack.
Release screws (1, 2).
Tightening torque 31 10 1AZ.
Installation note:
Check threads for damage; if necessary, repair with Helicoil thread inserts.
Tighten down first screws (1) and then screws (2).
IMPORTANT:
Risk of damage.
Follow operations must be carried out during lowering:
- Remove heat exchanger from front axle support and tie up.
- Remove anti-roll bar (conventional) from front axle support and tie up.
- Remove all hydraulic lines on front axle support or anti-roll bar retaining bracket and tie up.
- Version with active steering: Disconnect plug connection and expose connecting line up to hydraulic steering gear.
Lower front axle support by max. 10 cm.
