Specifications & Procedures Audi A4 B6

IDENTIFYING SUSPENSION VARIATIONS

Various suspensions are offered as options. These variations are identified by part numbers. Running gear version installed in vehicle is indicated by the factory weight code on the vehicle data plate. (Scheme 1) Vehicle data plate is located in spare tire well and in service book. The following table identifies suspension versions. Identifying proper suspension version is critical for wheel alignment. See IDENTIFYING SUSPENSION VARIATIONS table.

IDENTIFYING SUSPENSION VARIATIONS

Scheme 1

JACKING & HOISTING

FLOOR JACK

Always use a suitable rubber or wooden block to avoid damage. A floor jack can only be applied at the lifting points (Scheme 2)and (Scheme 3). On no account should the vehicle be lifted at the engine sump, transmission or front or rear axle, as this may cause serious damage.

Front

Support front of vehicle on the vertical reinforcement of the side member at the height of the marking for the on-board car jack. (Scheme 2)

Scheme 2

Rear

Support rear of vehicle on the vertical reinforcement of the side member at the height of the marking for the on-board car jack. (Scheme 3)

Scheme 3

PRELIMINARY CHECKS

Note. Vehicle alignment specifications will vary depending on suspension type. See IDENTIFICATION . Determine suspension type before starting alignment procedure.

Before beginning wheel alignment procedures, ensure following conditions are met.

1. All wheels and tires are of approved size (all 4 identical) and tires are properly inflated. Tread depth has no more than .08" (2 mm) difference between tires on same axle. Correct as necessary.
2. Vehicle is at normal curb weight. Curb weight of the vehicle ready for operation (full fuel tank, spare wheel, vehicle tool kit, jack).
3. Make sure alignment equipment turntable and sliding base are not on end stop.
4. Check steering and suspension components for looseness or damage. Correct as necessary.
5. Check wheel bearing play and condition. Correct as necessary.
6. Vehicle properly aligned, bounced several times and allowed to settle.
7. Perform wheel runout compensation. The permissible lateral runout of the rims may already cause the toe-in tolerance to be exceeded. The toe-in can then not be set correctly without performing wheel runout compensation.

VEHICLES WITH STEERING PULL

Pulling maybe caused by the steering gear not located exactly in the center when driving straight ahead. This causes a slight hydraulic steering support to left or right. The result is vehicle pull.

Perform an alignment on a vehicle complaint "Vehicle pulls or leads to one side", check that the rack is centered. The rack must be positioned exactly in the center in order to adjust the toe/toe constant.

VEHICLES WHICH HAVE BEEN IN AN ACCIDENT

Note. On vehicles which have been in an accident, before checking or adjusting toe or toe constant "S", steering rack must be positioned exactly in midway position. Centering bolt (VAG 1907) must be installed if wheel alignment is to be implemented on accident vehicles.

Place steering rack in midway position as instructed by wheel alignment computer.

Scheme 4

1. Remove screw plug (1) from steering rack. (Scheme 4)
2. Install bolt (2) for steering centering (VAG 1907). Screw in by hand as far as possible.
3. Turn steering wheel slightly to left and right of center position. Have second mechanic bolt into steering gear until engagement in centering hole is felt.
4. When installing screw plug (1), tighten to 16 ft. lbs. (22 N.m).
5. Check whether steering wheel is as close as possible to being horizontal on steering column with wheels facing straight ahead. If necessary, re-position steering wheel accordingly. Otherwise center position of rack is not guaranteed.

WHEEL ALIGNMENT PROCEDURES

Note. On vehicles with electronic chassis controls, ensure systems are functional before adjusting riding height or wheel alignment.

Note. While limited information is available, vehicle manufacturer does not support alignment information using aftermarket alignment equipment. To properly align vehicle, it is recommended to use VAG 1813 alignment computer. All procedures in this article are written using VAG 1813 alignment computer.

WHEEL ALIGNMENT WORK SEQUENCE

See PRELIMINARY CHECKS before starting wheel alignment. Perform wheel alignment in this order

1. Check and adjust (if necessary) front axle camber.
2. Check and adjust (if necessary) rear axle camber.
3. Check and adjust (if necessary) rear axle toe.
4. If necessary, check profile of front axle toe-in curve (toe constant "S").
5. Check and adjust (if necessary) front axle toe for vehicle curb weight.

CAMBER ADJUSTMENT (FRONT)

Note. Before attempting any adjustments, see PRELIMINARY CHECKS and WHEEL ALIGNMENT PROCEDURES .

Front wheel camber cannot be set separately. Camber can be evened out uniformly, by loosening subframe bolts and shifting subframe position until correct camber range is obtained. Use the following procedure.

Scheme 5

Scheme 6

1. Working under vehicle, remove noise insulation panel.
2. On convertible models, Remove outer front underbody trim. Remove front diagonal brace from under vehicle. (Scheme 5)
3. On all models, LOOSEN, but do not remove subframe bolts No. 1 through No. 8. (Scheme 6)
4. Slide subframe into respective position using a plastic coated tire iron. (Scheme 7) Press at center of subframe between subframe and body longmember. If no plastic coated tire iron is available, a standard tire iron must be wrapped with tape. See «WHEEL ALIGNMENT SPECIFICATIONS»(/audi/a4/b6-2000-2006/remont/wheel-alignment/#specifications-procedures__wheel-alignment-specifications).
5. If camber is within specified range, install NEW subframe bolts at positions No. 7 and No. 8. Tighten bolts No. 7 and 8 to 81 ft. lbs. (110 N.m), plus an additional 90°.
6. Install NEW subframe bolts at positions No. 6 and No. 5. Tighten bolts No. 5 and 5 to 81 ft. lbs. (110 N.m), plus an additional 90°.
7. Install NEW subframe bolts at positions No. 1, No. 2, No. 3 and No. 4. Tighten to 55 ft. lbs. (75 N.m).
8. On convertible models only, install diagonal brace. Tighten bolts to 41 ft. lbs. (55 N.m).
9. On all models, install noise installation panel. Recheck all wheel alignment settings and readjust as necessary.

CAMBER ADJUSTMENT (REAR)

Note. Before attempting any adjustments, see PRELIMINARY CHECKS and WHEEL ALIGNMENT PROCEDURES .

Note. Manufacturer recommends using NEW nut if original is loosened or removed.

1. Unfasten nut from wheel bearing housing/transverse link bolted joint (A). Adjust camber by turning eccentric bolt (B). (Scheme 8) See «WHEEL ALIGNMENT SPECIFICATIONS»(/audi/a4/b6-2000-2006/remont/wheel-alignment/#specifications-procedures__wheel-alignment-specifications). Maximum adjustment range is 90 to left or right from center position.
2. Fasten NEW nut. Tighten to 70 ft. lbs. (95 N.m). Recheck camber adjustment after tightening nut.

Scheme 7

TOE ADJUSTMENT (REAR)

Note. Before attempting any adjustments, see PRELIMINARY CHECKS and WHEEL ALIGNMENT PROCEDURES .

Scheme 8

Scheme 9

1. Remove floor pan panels in front of trapezoidal link. (Scheme 9)
2. On convertible models only, remove rear diagonal brace (1 or 2) from side on which toe needs to be adjusted. (Scheme 10) See «REAR DIAGNONAL BRACE (REMOVAL & INSTALLATION)»(/audi/a4/b6-2000-2006/remont/wheel-alignment/#specifications-procedures__rear-diagnonal-brace-removal-installation).
3. On all models, check rear toe value. See «WHEEL ALIGNMENT SPECIFICATIONS»(/audi/a4/b6-2000-2006/remont/wheel-alignment/#specifications-procedures__wheel-alignment-specifications).
4. If toe needs adjustment, loosen nut of bolt securing front inside of trapezoidal link to subframe. (Scheme 11) Adjust toe by turning eccentric bolt accordingly. Maximum adjustment range is 90 degrees to left or right from center position.
5. Tighten NEW nut to 70 ft. lbs. (95 N.m) with full vehicle weight on ground. Altering individual toe values automatically changes geometric drive axis as well. Double-check the toe value after tightening nut.
6. On convertible only, install diagonal brace. On all models, install floor pan panels.

Rear Diagnonal Brace (Removal & Installation)

Note. The securing bolts for diagonal brace are micro-encapsulated bolts. They must be replaced after removal.

Scheme 10

1. Remove floor pan panels in front of trapezoidal link. (Scheme 9)
2. Mark installed position of diagonal brace and body with felt pen before removal. (Scheme 12) Lower vehicle onto wheels. Remove diagonal brace bolts. Raise vehicle. Remove diagonal brace.
3. The residues of locking compound must be removed from all tapped holes using a tap. Position diagonal brace according to threaded holes or markings on body. Install NEW micro-encapsulated bolts, but do not tighten. Lower vehicle onto wheels and bounce several times. Tighten bolts to 41 ft. lbs. (55 N.m). Install floor pan panels in front of trapezoidal link.

TOE-IN CURVE ADJUSTMENT

Note. Before attempting any adjustments, see PRELIMINARY CHECKS and WHEEL ALIGNMENT PROCEDURES .

Note. An incorrectly adjusted toe-in curve adjustment causes the vehicle to pull to one side when braking or accelerating or when driving over bumps. Toe-in curve adjustment can also be referred to as toe constant "S" adjustment.

When the front wheels compress or rebound, the wheel's toe changes as a function of the compression and rebound travel. The resulting values are called toe-in curve. The wheel alignment computer determines the toe constant "S" from a value measured in initial position and a value measured in raised position. In the process it compares actual values with specified values and displays them on the screen.

Toe-in curve is adjusted when vehicle is in a raised position, by vertical adjustment of the tie-rod end. Different adapters are needed for lifting, depending on suspension variation. To prepare vehicle for checking toe-in curve adjustment, place vehicle in initial position. See BRINGING VEHICLE INTO INITIAL POSITION FOR ALIGNMENT (SUSPENSION VARIATIONS 1BA, 1BD, 1BE, 1BR & 1BV) .

Bringing Vehicle Into Initial Position For Alignment (Suspension Variations 1BA, 1BD, 1BE, 1BR & 1BV)

Due to the different alignment platforms, it may be necessary to raise vehicle at front axle so that it is possible to insert VAG1925 spacer. After vehicle is lowered, it should be bounced to resettle suspension. To place vehicle in initial position for alignment perform following

Scheme 11

Scheme 12

1. Install Spacer Gauge (VAG1925) with the adapters (VAG1925/3 or VAG1925/4).
2. Unscrew both thread spindles until they just come to rest against front bolts of carrier. (Scheme 13) This MUST NOT raise vehicle.
3. For sport suspensions 1BD, 1BE and 1BV only, position jack at front lifting point on body. Raise vehicle slightly and position Adapters (VAG 1925/6) on Apapters (VAG 1925/3 or VAG 1925/4) of spacer gauge. (Scheme 14) Lower vehicle onto adapter (arrow in (Scheme 14) ).
4. On all vehicle suspension types, vehicle is now in initial position.
5. At this point, alignment equipment program checks whether toe-in value per wheel is corresponds to a specification. See «WHEEL ALIGNMENT SPECIFICATIONS»(/audi/a4/b6-2000-2006/remont/wheel-alignment/#specifications-procedures__wheel-alignment-specifications). If toe is not as specified, adjust front toe-in to specification. See «TOE ADJUSTMENT (FRONT)»(/audi/a4/b6-2000-2006/remont/wheel-alignment/#specifications-procedures__toe-adjustment-front).
6. Place lifting jacks under front end jacking points and lift vehicle 2.4" (60 mm). With vehicle lifted as specified, extend cylinders in spindles and fix with locking pins. (Scheme 15) Ensure that locking pins are correctly positioned. Lower vehicle onto Spacer Gauge (VAG 1925).
7. Observe and compare toe-in constant "S" measurement on alignment computer to specifications. See «WHEEL ALIGNMENT SPECIFICATIONS»(/audi/a4/b6-2000-2006/remont/wheel-alignment/#specifications-procedures__wheel-alignment-specifications). If toe-in constant "S" measurement is as specified, check toe-in. See «TOE ADJUSTMENT (FRONT)»(/audi/a4/b6-2000-2006/remont/wheel-alignment/#specifications-procedures__toe-adjustment-front). If toe-in constant "S" measurement is not as specified, adjust as necessary. See «ADJUSTING TOE-IN CURVE (ALL MODELS)»(/audi/a4/b6-2000-2006/remont/wheel-alignment/#specifications-procedures__adjusting-toe-in-curve-all-models).

Scheme 13

Adjusting Toe-In Curve (All Models)

1. Before attempting toe adjustment, perform «BRINGING VEHICLE INTO INITIAL POSITION FOR ALIGNMENT (SUSPENSION VARIATIONS 1BA, 1BD, 1BE, 1BR & 1BV)»(/audi/a4/b6-2000-2006/remont/wheel-alignment/#specifications-procedures__bringing-vehicle-into-initial-position-for).
2. On tie rod end, loosen nut "A". (Scheme 16)and (Scheme 17).
3. Unscrew bolt "B" about.160" (4 mm). Press down on tie rod end until it stops.
4. Screw in adjustment bolt "B" until toe-in curve specified value is reached. See «WHEEL ALIGNMENT SPECIFICATIONS»(/audi/a4/b6-2000-2006/remont/wheel-alignment/#specifications-procedures__wheel-alignment-specifications).
5. Tighten nut "A" to 37 ft. lbs. (50 N.m). Recheck toe-in curve.
6. Tighten bolt "B" to 62 INCH lbs. (7 N.m).
7. Lower vehicle to initial position. Screw down spindle. Bounce vehicle with STANDARD suspension several times and allow suspension to settle.
8. Wheel alignment computer will check toe constant "S" value again. If values are as specified, recheck toe-in. See «TOE ADJUSTMENT (FRONT)»(/audi/a4/b6-2000-2006/remont/wheel-alignment/#specifications-procedures__toe-adjustment-front). If values are not as specified, repeat adjustment procedure.

Scheme 14

Scheme 15

TOE ADJUSTMENT (FRONT)

Note. Before attempting any adjustments, see PRELIMINARY CHECKS and WHEEL ALIGNMENT PROCEDURES .

Loosen lock nut "B" on tie rod. see scheme 18 Also, loosen rack boot outer clamp. Adjust toe by turning hex nut "A" until proper setting is reached. Do not allow boot to twist during adjustment, straighten twisted boots when toe in is set. Tighten tie rod lock nut to 30 ft. lbs. (40 N.m). Recheck toe adjustment.

Scheme 16

CASTER ADJUSTMENT (FRONT OR REAR)

Note. Before attempting any adjustments, see PRELIMINARY CHECKS and WHEEL ALIGNMENT PROCEDURES .

Front and rear caster are not adjustable. If caster is not as specified, locate and replace damaged or worn suspension parts.

WHEEL ALIGNMENT SPECIFICATIONS

FRONT AXLE WHEEL ALIGNMENT SPECIFICATIONS (A4 & S4)

REAR AXLE WHEEL ALIGNMENT SPECIFICATIONS (A4 & S4 - ALL VARIATIONS)

ADDITIONAL VEHICLE DATA

This additional vehicle data is merely intended to enable faster diagnosis in the event of minor accidents. see scheme 19

Scheme 17

See also:
• IDENTIFYING SUSPENSION VARIATIONS
• PRELIMINARY CHECKS
• WHEEL ALIGNMENT PROCEDURES
• WHEEL ALIGNMENT SPECIFICATIONS
• REAR DIAGNONAL BRACE (REMOVAL & INSTALLATION)
• BRINGING VEHICLE INTO INITIAL POSITION FOR ALIGNMENT (SUSPENSION VARIATIONS 1BA, 1BD, 1BE, 1BR & 1BV)
• TOE ADJUSTMENT (FRONT)
• ADJUSTING TOE-IN CURVE (ALL MODELS)