Clutches Audi A6 C4

DESCRIPTION

Clutch is single-plate, dry-disc type. Pressure plate is diaphragm spring type. Some models are equipped with a dual-mass flywheel. Bearing is operated by a clutch master cylinder, slave cylinder, push rod and release lever.

HYDRAULIC CLUTCH BLEEDING

Attach hose to bleeder fitting located on clutch release cylinder, next to hydraulic line. Submerge other end of hose in container half full of clean brake fluid. Fill reservoir with DOT 3 fluid. Open bleeder fitting. Have assistant press clutch pedal to full release position. Close bleeder fitting. Release clutch pedal. Repeat until air bubbles no longer emerge from hose. Refill reservoir.

CLUTCH PEDAL

Note. If clutch pedal is correctly adjusted but fails to return properly, inspect for seized pedal bushing or jammed return spring.

When engaged, clutch pedal should be .39" (10.0 mm) above brake pedal. If adjustment is required, loosen clutch master cylinder push rod locking nut, and rotate push rod until correct clutch pedal height is obtained. Ensure pedal return spring holds clutch pedal against stop pad.

DRIVE SHAFT

1. Remove front exhaust pipe and catalytic converter. Remove front crossmember and heat shield. Remove remaining exhaust pipe. Remove drive shaft crossmember. Loosen drive shaft mounting bolts.
2. Mount Drive Shaft Alignment Fixture (3139 ) to drive shaft. (Scheme 1) Tighten drive shaft alignment fixture plastic nuts. Remove center drive shaft bearing securing bolts and shims. Measure gap between vehicle body and center bearing mounting bracket. Install appropriate shims and install bolts. See «DRIVE SHAFT SHIMMING»(/audi/a6/c4-1994-1997/remont/clutches-manual-hydraulic/#clutches).
3. Push drive shaft to furthest rearmost position. Using center drive shaft bearing bracket as a guide, mark drive shaft position on vehicle body. Push drive shaft to furthest frontmost position and mark drive shaft position on vehicle body. Move drive shaft so that center bearing bracket is positioned between marks.

DRIVE SHAFT SHIMMING

Scheme 1

REMOVAL & INSTALLATION

Note. On models with theft protection system, obtain stereo security code from vehicle owner before disconnecting battery cable.

Removal

1. Remove battery cover. Disconnect negative battery cable. Remove upper transaxle-to-engine mounting bolts. Remove intake air ducting. Disconnect vehicle speed sensor and back-up light connectors. Remove all electrical connectors from transaxle.
2. Remove torque arm mounting bolts. (Scheme 2) Attach Engine Support Bridge (10-222A ) to left engine bracket. Support engine. Raise and support vehicle. Remove engine splash shield and bracket. Remove transaxle crossmember. Remove exhaust pipe and catalytic converter. Remove shift rod.
3. Disconnect automatic seat belt tension cables at transaxle. Remove inner CV joint heat shields. Remove drive shaft. Disconnect left and right axle shafts at transaxle. See the AXLE SHAFT article in DRIVE AXLES. If equipped, remove right heat shield. Remove starter wiring and starter.
4. Support transaxle using transmission jack. Remove left and right transaxle-to-subframe mounting bolts. Remove slave cylinder with fluid line attached. Remove lower transaxle-to-engine mounting bolts. Remove transaxle.
5. If reusing pressure plate, index mark position of pressure plate on flywheel. Loosen pressure plate mounting bolts evenly in a crisscross pattern. Remove clutch assembly.

Note. Pressure plate has a protective grease coating. Remove contact surface grease only. Service life will be shortened if remaining portions of pressure plate protective grease are removed.

Scheme 2

Inspection

1. Check flywheel for warpage, burn marks, grooves and excessive dowel pin wear. If necessary, resurface flywheel and replace dowel pins.
2. Check clutch pressure plate for burn marks and grooves. Using a straightedge and a feeler gauge, measure taper of pressure plate surface. Maximum taper is .012" (.30 mm). Check for grooves on diaphragm spring ends. Maximum groove depth is 1/2 thickness of spring end. Replace if necessary.
3. Check clutch disc for excessive wear, loose rivets, worn springs and oil contamination. Measure clutch disc runout using dial indicator with disc mounted on arbor between centers. Measure runout .098" (2.50 mm) from outer edge of clutch disc. Maximum runout is .020" (.50 mm). Replace clutch disc if necessary.

Installation

1. Ensure clutch disc slides freely with no radial play on input shaft. If equipped with a dual mass flywheel, clutch disc long hub end should face pressure plate. If not equipped with dual mass flywheel, clutch disc spring cage should face pressure plate. Lubricate input shaft splines with molybdenum grease.
2. Align pressure plate index marks. Use Clutch Disc Aligner (10-213 ) to center disc. Install NEW "O" ring and flywheel bolts. Install NEW clutch release bearing guide sleeve Torx bolts. Adjust drive shaft. See «DRIVE SHAFT»(/audi/a6/c4-1994-1997/remont/clutches-manual-hydraulic/#clutches__drive-shaft) under ADJUSTMENTS. To complete installation, reverse removal procedure. Bleed hydraulic system. See «HYDRAULIC CLUTCH BLEEDING»(/audi/a6/c4-1994-1997/remont/clutches-manual-hydraulic/#clutches__hydraulic-clutch-bleeding) .

Disconnect and plug fluid lines. Remove circlip and clevis pin. (Scheme 4) Separate push rod from clutch pedal. Remove master cylinder mounting bolts. Remove master cylinder.

To install master cylinder, reverse removal procedure. Ensure secondary cup sealing lips face piston and primary cup sealing lips face spring. Bleed master cylinder. See HYDRAULIC CLUTCH BLEEDING .

Remove transaxle. Remove cap bolt and 2 retainers at lower edge of release lever. Slide release lever and bearing out of bellhousing.

Check clutch release bearing for looseness and noise. If necessary, replace bearing.

Grease ball head stud located in clutch housing. (Scheme 3) DO NOT grease clutch release bearing guide sleeve. DO NOT wash bearing in solvent. Ensure clutch release lever contacts slave cylinder push rod tip. Grease push rod tip. To install, reverse removal procedure.

Scheme 3

1. Remove tensioning clamp. Remove slave cylinder lock pin located on top of transaxle. Slide cylinder back until push rod is clear. Disconnect and plug fluid line.
2. To install, reverse removal procedure. If cylinder is equipped with a plastic supporting ring, apply a light film of grease to outer face of ring before installing. Lubricate end of slave cylinder plunger. Bleed system at slave cylinder. See «HYDRAULIC CLUTCH BLEEDING»(/audi/a6/c4-1994-1997/remont/clutches-manual-hydraulic/#clutches__hydraulic-clutch-bleeding) .

OVERHAUL

Note. Manufacturer recommends replacement of faulty slave cylinder and does not provide overhaul procedures.

Scheme 4

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• DRIVE SHAFT SHIMMING
• DRIVE SHAFT
• HYDRAULIC CLUTCH BLEEDING