Alignment: Description and Operation
Wheel alignment
General
The vehicle alignment should be measured using VW/AUDI approved wheel alignment equipment!
We recommend that the front and rear axles are measured when performing alignment measurements.
Otherwise correct vehicle performance is not guaranteed and an off center steering wheel may exist.
Note:
^ Perform alignment only after 1000 - 2000 km (600 - 1200 miles) to allow suspension time to settled.
^ The individual specifications should be followed as exactly as possible when making adjustments.
If the installation position of the rear axle and the direction of travel of the vehicle is not taken into account an off center steering wheel may occur.
Steering wheel and steering column are marked.
These positions must not be changed!
A - Marked line on steering wheel
B - Punch mark on steering column
Otherwise the center position of the steering rack cannot be guaranteed!
Vehicles with Electronic Stabilization Program (ESP)
If the steering wheel is off-center, the basic setting for the Steering angle sensor G85 must be checked. Perform basic setting in "Guided fault finding" with the VAS 5051..
Steering columns supplied as a spare part do not have a center punch mark.
After wheel alignment and following test drive the steering column must be marked.
Part 1:
Part 2:
Wheel alignment is necessary when:
^ The vehicle handles poorly.
^ Components were damaged and have been replaced.
^ Axle components were removed.
^ Tire wear patterns are uneven.
Test Requirements:
^ Check suspension, wheel bearing, steering and steering linkage for excessive play and damage.
^ Tire tread depth difference of no more than 2 mm on an axle.
^ Tires inflated to correct pressure
^ Vehicle unladen
Fuel tank must be full
Spare wheel and vehicle tools are stowed at correct installation locations.
The fluid reservoir for the windshield/headlight washer system must be full.
^ Make sure that the sliding plates and turn tables (alignment equipment) are not touching the end stop when checking wheel alignment.
^ Do not check vehicle alignment before vehicle has completed 1000 to 2000 km (600 to 1200 miles), to allow coils springs to settle.
Note: The test equipment must be properly adjusted and attached to the vehicle; observe manufacturer's operating instructions.
Adhere to manufacturer of your vehicle alignment equipment for training as required.
Vehicle alignment platforms vehicle alignment units/vehicle alignment computers can lose their calibration over a period of time.
Vehicle alignment platforms and vehicle alignment units/vehicle alignment computers should be checked and if necessary adjusted within the framework of an inspection/maintenance at least once a year!
- Treat these highly sensitive units carefully and conscientiously!
Preparations for measurements
Special tools, testers and auxiliary items required
- Brake pedal depressor V.A.G. 1869/2
- The lateral runout of the wheel must be compensated for. Otherwise the result of the measurement will be incorrect.
- If the lateral runout compensation is not performed it is not possible to adjust the toe correctly!
- When doing this observe information from the manufacturer of the wheel alignment unit.
- Carry out wheel run-out compensation.
- Lower vehicle and bounce springs.
- Install brake pedal loading device V.A.G. 1869/2 .
- Press brake pedal with brake pedal depressor.
Vehicle trim height "Zero position"
In general!
- If a value lies outside the tolerance, the vehicle's trim height must be checked first.
- If the measured values are outside the allowed tolerances, the cause may be an incorrect vehicle attitude.
- Right-hand drive vehicles or for example vehicles with automatic transmission can lean to one side slightly.
This is due to the installation position of components and weight distribution
- It is absolutely necessary to measure dimension - a - on left and right sides.
- The O line on the roof means the horizontal position (zero position) of the vehicle.
- Correct differences if necessary.
- It is possible to correct trim height imbalance for front axle by adding weight to top of strut tower through the engine compartment.
- To correct trim height imbalance for rear axle add weight to top of strut tower through the trunk compartment.
For weight sand bags are suitable for example, approximately 10 kg (22 lb).
Vehicle data sticker
Explanation of the PR No. (factory codes) on the vehicle data sticker
Various suspension components are installed depending on engine and equipment level. They are indicated by the PR numbers (they are also known as factory codes).
The suspension components installed on the front axle in the vehicle is documented on the vehicle data sticker with the relevant PR. number.
Example of a vehicle data sticker
In this example the vehicle is equipped with the standard suspension 1 GA - arrow - .
The PR No. can also be e.g. G08, G29, G46 G76 etc.
The vehicle data sticker is located in spare wheel well and in Maintenance booklet.
The PR numbers determine the specified value allocation for the vehicle.