Removing and Installing Power-Steering Gear
WM 489019 Removing and installing power-steering gear
Preliminary work
Preliminary work
1. Raise the vehicle.
2. Remove front wheels.
3. Remove front underbody panel.
General warning notes
General warning notes
Caution: Increased risk of accidents if too much Pentosin is used or if Pentosin comes into contact with the coolant hoses when filling or topping up.
^ Possible danger of injury or damage.
--> Multiple steering operations (maneuvering) with the engine switched off change the fluid level in the reservoir. In this case, the engine must be running immediately prior to the fluid level check.
--> If coolant hoses come into contact with Pentosin, clean them thoroughly with water IMMEDIATELY.
--> Replace visibly swollen coolant hoses.
Information:
^ Before the feed and return lines are loosened, place a suitable container underneath to collect steering fluid.
^ Wear protective goggles and gloves.
Removal
Removing power-steering gear
Information: Fix the steering wheel with the wheels in straight-ahead position or remove the steering wheel with the wheels in straight-ahead position. If this is not done, the airbag contact unit will have to be put in center position after installation of the steering gear.
1. Loosen universal joint (steering shaft) on steering gear -Arrow-. To do this, take out the clamping screw and slide the joint upwards.
Universal joint
2. Press tie-rod end out of the steering arm. Press-out tool P 9560 (ball-joint extractor) must be used to do this. When loosening the lock nut, counter with a screwdriver P 9546 (Torx screwdriver).
3. Repeat the procedure on the other side.
4. Loosen feed and return lines at the steering gear. To do this, loosen the hexagon socket head bolt -Arrow- and remove the retainer plate. Plug the lines or use a collecting container. Cover lines if necessary (danger of soiling).
Retainer plate
5. Loosen the two steering-gear fastening screws (on the underside of the cross member).
6. Loosen mount for coolant pipes on the front-axle cross member (two supports on each side of the mount with M6 screws and a plastic clip at the front in the middle of the cross member).
7. Loosen screws -1+2- on the two diagonal braces (at the front).
Cross member with diagonal braces on body
8. Lower vehicle to working height (lower platform lift) and support cross member with a hydraulic lift (use a hard rubber base or wooden block: -see Figure- ).
Cross member support
9. Loosen threaded connections -3+4- securing cross member to body (front) and threaded connections -5+6- securing cross member with diagonal arm to body (front) (screws -1+2- have already been removed).
Cross member with diagonal brace to body
10. Loosen threaded connections securing cross member to body (rear): -7+8-, screw out -9+10- by approx. 10 mm.
11. Lower front cross member slightly (approx. 50 to 60 mm).
12. Pull out steering gear to the left (to the right for right-hand drive vehicles).
Information: Ensure that no damage (scoring) is caused to the steering rack. To loosen and tighten the tie rods, secure the steering gear on a suitable plate.
13. If necessary, loosen and remove right and left tie rods on the steering gear.
Tie rod on steering gear
Installation
Installing power-steering gear
Information: When topping up or filling in Pentosin, make sure that it does not come into contact with the coolant hoses. Observe the specifications in order to avoid overfilling, and thus overflowing.
^ If coolant hoses come into contact with Pentosin, clean them thoroughly with water IMMEDIATELY.
^ Replace visibly swollen coolant hoses.
^ Tighten all threaded connections to the specified tightening torque.
Install in reverse order. It is essential to observe the following points while doing so:
- Replace steering-gear fastening screws, the fit bolt on the steering shaft and the steering-wheel fastening screw whenever they have been removed. Screw threads must be clean and free of grease.
- Make sure that the steering rack is not damaged (scored).
- Fit the tie rods on the steering rack before installing the steering gear. Then secure the respective bellows with new clamping rings.
Tie rod on steering gear
- Fix steering gear in place on the front-axle carrier using the two fastening screws (for ease of assembly, just insert fastening screws). Position red plastic clip on steering-gear pinion and join universal joint (steering shaft) to the steering gear at the correct position - steering gear and steering wheel or airbag contact unit (spring) in center position.
The plastic clip ensures that the fastening screw between the universal joint and steering pinion sits into the groove on the steering pinion.
Universal joint for steering gear
- Observe following notes for sliding piece and airbag contact unit!
Notes for sliding piece and airbag contact unit
1. If the sliding piece -1- was pulled off the steering shaft -4-, the notch -2- must point towards the tooth gap -3- during assembly.
Sliding piece
2. If the steering wheel was not fixed before the steering gear was removed, the position of the contact unit (spring) may no longer be correct. In this case, remove steering wheel and move contact unit to center position because otherwise the spring will be damaged.
Contact unit in center position
- To position the airbag contact unit in center position, press the latch -D- and carefully turn the rotor -A- anti-clockwise as far as it will go.
Then (starting from the left end stop) carefully turn the rotor -A- clockwise by approx. 3.5 to 3.75 turns until the band printed on one side is visible in the window.
Before fitting the steering wheel, turn the front wheels to the straight-ahead position (steering shaft fitted on steering gear).
Contact unit
Subsequent work
Subsequent work
1. After fitting the pressure lines, fill steering hydraulics with Pentosin and bleed the steering system.
2. Fit front underbody panel.
3. Fit front wheels.
4. Adjust toe. Calibrate steering-angle sensor if necessary.