Porsche 996 TT, Repair Manual

Page: 330 / 2099

the following points should be given special attention:
Empty weight of vehicle in accordance with DIN 70020, i.e. car ready for the road, with full fuel tank,
spare wheel (collapsible wheel) and tools. •
Ball−joint and wheel−bearing play in order (wheel−bearing play cannot be adjusted).
•
Tyre pressure in accordance with regulations, fairly uniform tyre tread. •
Quick−clamping holder for the 911 Turbo with adapter (for the measured−value pickups) correctly
secured to the wheels. •
Receiving surfaces for the quick−clamping holder on the wheels and the adapter surfaces must be
clean and flat. Always check the levelling surface on the wheels precisely in particular before fitting
the quick−clamping holders. •
Strictly comply with maintenance intervals for measuring equipment and measuring platform. If the
levelling of the measuring platform or of the measuring area is done in−house, levelling equipment is
required. A hose level is inadequate! •
Skilled handling of measuring equipment and measuring platform.
•
Sliding plates with transverse motion (rotary motion) at the rear axle are advisable. •
Observe the Technical Literature of PAG, the manufacturer of the measuring equipment and the
manufacturer of the measuring platform. •
Do not treat measured values as a whole, but very critically in regard to driving dynamics, high−speed
strength of the tyres, tyre wear and cost/benefit effects (time required for correction of insubstantial
deviations). The toe values are of decisive significance for driving dynamics and tyre wear. •
If the vehicle is measured front and rear, check and adjust the wheel alignment values at the rear axle
first. Camber values at the front axle apply for the straight−ahead position of the wheels. Steering
wheel and steering gear in centre position when toe is being adjusted. •
Before wheel alignment values are adjusted at front and rear axles, it is recommended that the vehicle
height be checked at the DIN empty weight. Conclusions can then be drawn about wheel alignment
values in the event of any suspension alignment that becomes necessary later.
•
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Vehicle height (vehicle height check)
General
Note
The vehicle height at front and rear axle is not adjustable! •
Preliminary work
1. For the height check, place the vehicle on a level surface or on the measuring platform (ready to
drive, with a full tank, spare wheel and tools).
2. Compress vehicle at front and rear by approximately 25 mm 2−3 times and allow it to spring back
freely.
einordnung
General procedure for suspension alignment 267