General, Technical Data (Suspension, Wheels, Steering (roadster)) Audi TT 8J

WHEELS AND TIRES

General information on wheel/tire combinations, winter tires, snow chain and recommended tire manufacturers, refer to WHEELS AND TIRES .

FRONT GAS-FILLED STRUT, VENTING

Secure gas-filled shock absorber vertically in vise, with piston rod facing down.

Scheme 1

Drill a 3 mm hole -arrow A- through outer tube of shock absorber.

Note. Gas escapes when drilling.

Continue drilling until tube inside is drilled through (approximately 25 mm deep).

Drill a 6 mm hole -arrow B-, through outer and inner strut tubes.

Hold shock absorber over appropriate container for catching oil and move piston rod repeatedly through entire stroke until no more oil flows out.

REAR GAS-FILLED STRUT, VENTING

Secure gas-filled shock absorber vertically in vise, with piston rod facing down.

Scheme 2

Drill a 3 mm hole -arrow A- through outer tube of shock absorber.

Note. Gas escapes when drilling.

Continue drilling until tube inside is drilled through (approximately 25 mm deep).

Drill a 6 mm hole -arrow B-, through outer and inner strut tubes.

Hold shock absorber over appropriate container for catching oil and move piston rod repeatedly through entire stroke until no more oil flows out.

AUDI MAGNETIC RIDE (AMR) FRONT SHOCK ABSORBERS, VENTING

Clamp magnetic ride shock absorber vertically in vise.

Scheme 3

Drill a 3 mm hole -arrow A- through outer tube of shock absorber.

Note. Gas escapes when drilling.

Drill a second 6 mm hole -arrow B- through outer tube of shock absorber.

Hold shock absorber over appropriate container for catching oil and move piston rod repeatedly through entire stroke until no more oil flows out.

AUDI MAGNETIC RIDE (AMR) REAR SHOCK ABSORBERS, VENTING

Clamp magnetic ride shock absorber vertically in vise with piston rod facing down.

Drill a 3 mm hole -arrow A- through outer tube of shock absorber.

Note. Gas escapes when drilling.

Drill a second 6 mm hole -arrow B- through outer tube of shock absorber.

Hold shock absorber over appropriate container for catching oil and move piston rod repeatedly through entire stroke until no more oil flows out.

SHOCK ABSORBERS, LEAKING

Shock absorbers are frequently rejected and exchanged because of leaks. Examinations on the test stand and on the vehicle have shown that the replacement of a large number of rejected shock absorbers was not justified.

Slight leaking of oil ("sweating") at piston rod seal is no reason to replace a shock absorber. A shock absorber damp with oil is OK under the following circumstances

Scheme 4

1. Oil leak (shown screened in illustration) is visible, but dull, matte and possibly dry from dust
2. Oil excretion extends from upper shock absorber connection (piston rod oil seal) no further than lower spring plate -arrow

CHASSIS

SHOCK ABSORBERS, REMOVED, CHECKING

Defective shock absorbers are noticeable when driving due to loud rumbling noises - a result of wheel hopping - especially on poor stretches of road. Moreover, they can be recognized by a large loss of oil.

Note. Shock absorbers are maintenance-free, shock absorber oil cannot be topped off.

A removed shock absorber can be checked by hand as follows

Press shock absorber together by hand.

1. Piston rods must move smoothly and with uniform difficulty over the entire range

Release piston rods.

1. On shock absorbers with sufficient gas pressure, piston rods return to initial position by themselves.

Note. If this is not the case, shock absorber must be replaced. As long as there is no large loss of oil, the mode of operation corresponds to that of a conventional shock absorber. The damping function is also completely available without gas pressure, as long as there is no large loss of oil. However, noise may increase.

SHOCK ABSORBERS, CHECKING ON SHOCK TESTER

Note. Shock absorbers can be checked while installed using the shock tester (shock absorber testing device). The damping effect can be evaluated based on the dial reading or print-out.

Special tools and workshop equipment required

1. Boge shock tester or
2. Sachs shock tester V.A.G 1975 or
3. Maha shock absorber tester VAS 1990

Note. Temperature +10 to +40 °C. Driver in vehicle. The vehicle is stationary. Tire pressure OK. Drive vehicle straight onto center of wheel contact plates. Front wheels in straight position. Parking not engaged, foot brake not activated. The ignition is switched on. On vehicles with Audi magnetic ride (AMR) - electronically controlled damping, test mode is active.

ACTIVATING TEST MODE FOR AUDI MAGNETIC RIDE (AMR) - ELECTRONICALLY CONTROLLED DAMPING

Press the damping adjustment button -E387- (refer to item 4 in: AUDI MAGNETIC RIDE (AMR) - ELECTRONICALLY-CONTROLLED DAMPING ASSEMBLY OVERVIEW ) inside the center console or instrument panel for 5 seconds. The indicator lamp inside the damping adjustment button will start blinking to confirm that the test mode is working.

Press the dampening adjustment button again, switch the ignition or drive at least 10 km/h to end test mode.

Threshold

Shock absorber condition can only be judged as follows

1. Sufficient damping effect

or

1. Insufficient damping effect

Note. Intermediate values for reduced damping performance cannot be read out. A prognosis on service life is not permitted. Measured values that come about from involvement of suspension travel end stops are incorrect.

The following values apply only to the test stands named above. If values specified are exceeded, the shock absorber has lost enough of its efficacy that a replacement is recommended.

Example

Scheme 5

Threshold = 70

1. a- = greater than 70: Insufficient damping effect
2. a- = less than 70: Sufficient damping effect

Threshold "a" in mm

Note. If the readout value is greater than the limit value "a" (table value): Damping effect insufficient --> Replace shock absorber. If the readout value is less than the limit value "a" (table value): Damping effect sufficient --> Shock absorber does not need to be replaced.

VEHICLES WITH AUDI MAGNETIC RIDE (AMR) - ELECTRONICALLY-CONTROLLED DAMPING

Note. These values only apply when test mode is active. Refer to ACTIVATING TEST MODE FOR AUDI MAGNETIC RIDE (AMR) - ELECTRONICALLY CONTROLLED DAMPING . The indicator lamp in the dampening adjustment button -E387- blinks to indicate when test mode is active. Refer to item 4 in: AUDI MAGNETIC RIDE (AMR) - ELECTRONICALLY-CONTROLLED DAMPING ASSEMBLY OVERVIEW .

See also:
• WHEELS AND TIRES
• AUDI MAGNETIC RIDE (AMR) - ELECTRONICALLY-CONTROLLED DAMPING ASSEMBLY OVERVIEW
• ACTIVATING TEST MODE FOR AUDI MAGNETIC RIDE (AMR) - ELECTRONICALLY CONTROLLED DAMPING