Steering Gear: Service and Repair
Removing and installing steering gearTools
Preliminary work
Note:
^ Fix steering wheel with wheels in straight-ahead position (engage steering column lock or clamp steering wheel in center position with steering wheel holder). If this is not done, the airbag contact unit will have to be put in the center position after installation of the steering gear.
^ Before the feed and return lines are loosened, place a suitable container underneath to collect steering fluid.
^ Wear protective goggles and gloves.
1. Remove wheel.
2. Remove engine guard.
3. Remove wheel-housing liner.
Removing steering gear
Note:
^ Fix steering wheel with wheels in straight-ahead position (engage steering column lock or clamp steering wheel in center position with steering wheel holder). If this is not done, the airbag contact unit will have to be put in the center position after installation of the steering gear.
^ Before the feed and return lines are loosened, place a suitable container underneath to collect steering fluid.
^ Wear protective goggles and gloves.
1. Remove the outer tie rod joints with the press-out tool T10187. When pressing off, screw lock nut on flush (protects the ball joint thread).
2. Remove fastening screws -arrows- from heat shield (steering gear/steering shaft). If vehicle is a Cayenne with Servotronic, pull off connector.
3. Remove fastening screw from universal joint of steering shaft -arrow- (push universal joint slightly upwards).
4. Release rear mount of front-axle drive (right-hand side of vehicle). Lift front axle drive with a suitable jack -see figure-(use wooden block or rubber base to prevent slipping. Remove fastening screw and lift front-axle final drive just enough to access the bearing eye above the bolting point of the front axle carrier (do not press the cardan shaft into the stop).
5. Re-insert fastening screw -arrow- (better access). The drive remains in the raised position and the jack can be removed.
6. Release supply and return lines -arrows- (collect steering fluid in a suitable container). Close the lines and any open threaded bores with suitable plugs.
7. Remove the fastening screws of steering gear -arrows-.
8. For easier removal of the steering gear, loosen the fastening nut on the coolant hoses. Then unclip coolant hoses from brackets and lay them upwards -see figure- (cut-away view of steering gear shown here).
9. Remove heat shield and push steering gear -see figure- to the right, out of the subframe mounting points, and turn to the rear.
10. Turn steering gear -arrow- to the rear by approximately 90-100 degrees.
11. Unclip the coolant hoses in the wheel housing from the retaining clip. Then carefully guide out steering gear -see figure- through the left wheel housing.
Installing steering gear
WARNING:
Risk of accident due to malfunction in PSM control range if steering-angle sensor is not calibrated or is incorrectly calibrated.
^ Possibility of serious injury or material damage.
^ Calibrate steering-angle sensor with wheels in straight-ahead position using the Porsche System Tester.
^ If steering wheel has been removed, ensure that airbag spiral spring is in center position.
Note:
^ When topping up or filling in Pentosin, make sure that it does not come into contact with the coolant hoses. To avoid overflow caused by overfilling, observe the instructions.
^ If coolant hoses come into contact with Pentosin, clean them thoroughly with water IMMEDIATELY!
^ Replace visibly swollen coolant hoses.
After fitting the pressure lines, fill steering hydraulics with Pentosin CHF 11 S and bleed steering system.
Replace all elastic bolts and lock nuts.
Tighten all threaded connections with the specified tightening torque values.
Check and/or adjust toe-in.
Calibrate steering-angle sensor.
Information
Installation instructions
Installation is in reverse order.
Replace fastening screw of steering shaft whenever it has been removed. Ensure it is fitted correctly. Insert fastening screw (in correct position, not from the threaded side).
Push on universal joint (steering shaft) in correct position, with steering gear and steering wheel or airbag contact unit (spiral spring) in center position. When doing this, only place steering transmission screws in position (to facilitate assembly when pushing universal joint on). After the fastening screws of steering have been tightened, push universal joint on as far as it will go. When fitted correctly and tension-free, the universal joint is allowed to be at a maximum distance -arrows- of 4 mm from the outermost edge of steering gear dust boot.
Replace steering gear fastening screws.
Screw threads must be clean and free of grease.
Ensure that no damage (scoring or similar damage) is caused to the steering rack.
If the tie rods are to be reused, detach them from removed steering gear and fit them on new steering gear. Insert new sealing rings -arrow- on steering gear.
Note
^ The left clamp of the joint boot must be clamped so that the clamp lug -arrow- is in line with the steering pinion.
^ The right clamp of the joint boot must be clamped so that the clamp lug -arrow- points horizontally with the front axle carrier (suspension subframe) in the direction of travel.
^ Failure to do this can lead to constrictions on the left-hand side in the vicinity of the feed and return lines and on the right-hand side in the vicinity of the heat shield.
Fit joint boot (not twisted) and secure with new clamps -arrow- (use pliers for hose clamp NR.74, Workshop Equipment Manual, commercially available tools).
Check the joint boot is not worn (cracks, slots) and that sealing surfaces are clean.
When fitting the ball joints, ensure that the conical seats are clean.
Remove dirt or grease on conical seats, e.g. with a lint-free cloth. Do not use cleaning agent/solvent.
Observe airbag safety instructions.
Install airbag unit for driver.
Observe notes on steering-gear center position in the section on front track adjustment in Repair Group 44.
Calibrate steering-angle sensor.
Observe correct tightening torques.