General Repair Information
The maximum possible care, cleanliness and proper tools are essential to ensure satisfactory and successful steering gear repairs. Understandably, general safety guidelines apply when performing repairs.
A series of applicable general notes for individual repair procedures - otherwise listed several times at many points in the repair information - has been collected here. They apply for this repair information.
A description of the construction and function of this steering system can be found in Self Study Program No. 317, Electromechanical Power Steering with Double Pinion.
Steering Gear
- Thoroughly clean connecting points and their surrounding areas before loosening.
- When installing steering gear, make sure centering sleeves are correctly seated between console and steering gear.
- Place removed parts on a clean surface and cover to prevent contamination. Use foils and paper. Do not use fluffy cloths!
- Only install clean components: Only unpack replacement parts immediately prior to installation.
- Use exclusively lubricants and sealants marked with part numbers.
- Carefully cover over opened components or seal, if repairs are not carried out immediately.
- As of MY 2009 steering gear generation 3 is being installed. Information on the differences between generation 2 and generation 3, refer to STEERING GEAR, GENERATION 2 AND GENERATION 3 DIFFERENCES .
Gaskets and Seals
- Always replace seals and gaskets.
- After removing seals, inspect contact surface on housings and shafts for burrs and damage and repair if necessary.
- Remove all residual sealant of fluid seals from sealing surfaces, no sealant residue must enter the steering gear housing when doing this.
Bolts and Nuts
- Loosen and tighten the bolts and nuts of covers and housings in a diagonal sequence.
- Do not cant but loosen and tighten especially sensitive parts in diagonal manner in stages, e.g. servo motor with control module.
- Torque specifications for unoiled bolts and nuts are given.
- Always replace self-locking nuts and bolts.
Electrical Components
Surely everyone has been shocked at one time or another when coming into contact with a metal object. The reason for this is the build-up of static electricity in the human body. This charge can lead to functional problems by touching the electrical components of steering gear.
-- Touch a grounded object - for example a water pipe or a vehicle hoist - before working on electrical components. Do not make direct contact on connector terminals.
Guided Fault Finding, OBD and Test Instruments
- Before performing repairs on electro-mechanical steering, the malfunction cause must be determined as exactly as possible using Vehicle Diagnostic, Testing and Information System VAS 5051 in operating modes "Guided Fault Finding", "Vehicle Self-Diagnosis" and "Test Instruments".