Differential & Drive Shaft Audi A4 B5

AXLE RATIO & IDENTIFICATION

Identification code is stamped on differential housing. (Scheme 1)

AXLE RATIO APPLICATION

Scheme 1

DESCRIPTION

Rear differential assembly is hypoid gear type using integral carrier housing. Vacuum operated differential lock is used to engage differential. Differential lock can be applied manually up to 16 MPH. Differential lock switch located in cover of rear console. Lock disengages automatically greater than 16 MPH.

FLUID TYPE & CAPACITY

Use API GL-5 gear oil. Fluid capacity is 1.8 qts. (1.7L).

TROUBLE SHOOTING

Note. See TROUBLE SHOOTING - BASIC PROCEDURES article in GENERAL INFORMATION.

DRIVE SHAFT ALIGNMENT

Note. Driveshaft universal joints and bearings are not serviceable. Replace driveshaft as an assembly if damaged.

Removal, Installation & Alignment

1. Using a 2 column lift, raise and support vehicle. Remove complete exhaust system and heat shields. Remove crossmember below driveshaft. Place match marks on driveshaft flange to final drive flange. Loosen driveshaft mounting bolts at transmission and final drive. Loosen center bearing mount bolts.
2. Attach Alignment Fixture (3405) and tighten plastic nuts. Remove driveshaft mounting bolts at transmission and final drive. Supporting driveshaft and alignment fixture, remove center bearing mounting bolts and shims. Remove driveshaft with alignment fixture. NOTE: Ensure threads in transmission and differential flange are free of any locking compound residue or debris before reassembly. Always install NEW self locking bolts.
3. To install, reverse removal procedure. Before removing alignment fixture, measure distance "A" between center mounting bracket and body to determine thickness required. Left and right side shims must be equal. See «CENTER BEARING SHIM THICKNESS»(/audi/a4/b5-1994-1999/remont/differentials-drive-axles/#differential-drive-shaft) table. CENTER BEARING SHIM THICKNESS Distance "A" In. (mm) Shim Thickness In. (mm) Part Number 0-.012 (0-3) - No Shim Used.012-.199 (3.1-5) 2 857 521 143.200-.278 (5.1-7) 4 857 521 143 A.279-.357 (7.1-9) 6 857 521 143 B.358-.436 (9.1-11) 8 857 521 143 C.437-.512 (11.1-13) 10 857 521 143 D
4. Center driveshaft front to rear. With alignment fixture installed, push driveshaft rearward to stop. Mark position "A" of center bearing, at body. Push driveshaft forward to stop. Mark position "B" of center bearing, at body. Set driveshaft to center position "C" using position "A" and "B". (Scheme 2) Install center bearing bolts with selected shims and tighten to specification.
5. Remove alignment fixture. Install heat shield and exhaust system. Install crossmember below exhaust system. Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(/audi/a4/b5-1994-1999/remont/differentials-drive-axles/#differential-drive-shaft__torque-specifications).

Scheme 2

AXLE SHAFT

Note. See AXLE SHAFTS - RWD article in DRIVE AXLES section for axle shaft removal, installation and overhaul.

REAR HUB & BEARING ASSEMBLY

Note. See AXLE SHAFTS - REAR article in DRIVE AXLES section for rear hub and bearing removal, installation and overhaul.

Removal (Right Side)

1. Unbolt and remove undercover. Disconnect parking brake at right caliper. Support trapezoidal arm with transmission jack. Disconnect trapezoidal arm from crossmember. Carefully lower with transmission jack and vehicle jack support. Remove parking brake cable out of holder. Disconnect axle shaft from flange. Move trapezoidal arm to right and lower axle shaft.
2. Install 2 bolts into flanged shaft and hold with pry bar. Remove Torx head screw in center of flange. Place oil drain pan below and remove flanged shaft. Pry out seal.

Installation

Drive in NEW flanged shaft seal. Install flanged shaft and drive axle. Check gear oil level and fill as needed. Attach parking brake cable and replace undercover. Tighten all bolts to specification. See TORQUE SPECIFICATIONS .

Removal (Left Side)

1. Remove silencer. Remove undercover. Remove parking brake cable from holder. Support trapezoidal arm with transmission jack. Disconnect trapezoidal arm from crossmember and carefully lower and support with stand. Disconnect axle shaft from flange. Move trapezoidal arm to left and lower axle shaft.
2. Drain gear oil. Install 2 bolts into flanged shaft and hold with pry bar. Remove Torx head bolt from center of flanged shaft. Remove flanged shaft and shim. Pry out seal. (Scheme 3)

Using Seal Installer (3066/1), install NEW flanged shaft seal. Install flanged shaft and axle shaft. Loosen cover at right rear and fill differential with specified gear oil. See FLUID TYPE & CAPACITY . Bolt on trapezoidal arm. Install parking brake cable to holder and install undercover. Tighten all bolts to specification. See TORQUE SPECIFICATIONS .

Scheme 3

Removal

1. Raise and support vehicle. Remove undercover. Remove silencer and heat shield above. Paint match marks on axle shaft and differential. Disconnect driveshaft at rear flange. Using wire, hang up driveshaft only far enough to clear final drive.
2. Unbolt left side cover plate. Unbolt differential lock vacuum element holding bracket from differential. Remove vacuum element, selector fork connecting pin, and rubber boot. Remove parking brake cable with rubber grommet out of holding bracket. Disconnect differential lock switch wiring harness. Disconnect vacuum hoses from vacuum element, noting colored makings for reassembly.
3. Disconnect right parking brake cable bracket from final drive. Disconnect right and left axle shafts and hang with wire. Remove heat shield and disconnect parking brake cables at body. Using transmission jack, support differential. Remove right side bolt of crossmember I and carefully lower. Separate crossmember II from crossmember I. Remove left side crossmember I bolt and remove crossmember I over differential flange. Lower differential assembly.

To install, reverse removal procedure. Ensure bracket for right side parking brake cable is installed before differential is bolted tight. Ensure vacuum hoses are correctly connected. (Scheme 5) Align match marks on driveshaft with flange. Tighten all fasteners to specification. See TORQUE SPECIFICATIONS.

DIFFERENTIAL ASSEMBLY

Note. If replacing bearing, replace both differential tapered roller bearings of alike manufacturer. Overhaul of 90 differential assembly is similar to that of models listed.

Disassembly

1. Clamp differential in Repair Stand (VW 540). Remove torque tube. Remove axle shaft flanges. See «SIDE GEAR SHAFT OIL SEAL»(/audi/a4/b5-1994-1999/remont/differentials-drive-axles/#differential-drive-shaft) . Remove cover from differential housing. Remove differential carrier. Using Bearing Race Remover (VAG 1582) and Adaptor (VAG 1582/6), remove large tapered roller bearing inner race from gear housing. Using puller, remove small tapered roller bearing inner race from gear housing.
2. Place match marks on ring gear and gear housing. Remove ring gear from gear housing. Drive out spring pin, remove pinion shaft and 4 pinion gears (2 large, 2 small), 2 shims, 2 thrust washers, 2 threaded washers.
3. Drive out large tapered roller bearing outer race out of cover. Remove spacer, noting its thickness. Drive out small tapered roller bearing outer race out of final drive housing.
4. Remove pinion gear. Using Drive Pinion Nut Tightening/Loosening Tool (2052/2), Case Adaptor (3132) and 32 mm socket, remove pinion nut. Press pinion out of small tapered roller bearing. Remove small tapered roller bearing outer race. Using Bearing Race Removal Tool (3138), remove large tapered roller bearing outer race. Press large tapered bearing off pinion gear.

Reassembly

1. Heat NEW bearing to 212°F (100°C) and press onto pinion gear. Install pinion gear selected spacer shim (S3). See «ADJUSTMENTS»(/audi/a4/b5-1994-1999/remont/differentials-drive-axles/#differential-drive-shaft) . Install large tapered roller bearing outer race to differential housing. Install small tapered roller bearing outer race. Install pinion with NEW spacer sleeve. Heat small tapered roller bearing to 212°F (100°C), and install bearing.
2. Measure friction torque. Using torque gauge and 32 mm socket, adjust friction torque to 18-22 INCH lbs. (200-250 N.m) with NEW bearings. With USED bearings, adjust friction torque to 3-5 INCH lbs. (30-60 N.m). Increase tightening torque slowly and read friction torque often. If specific friction torque is exceeded, replace spacer sleeve and repeat adjustment. Using drift, stake drive pinion nut through oil drain hole.
3. Clean and inspect parts for wear, pitting or cracks. Replace as necessary. Install large and small outer tapered roller bearing races. Install large pinion gears with thinnest shim .002" (.5 mm). Apply grease to thrust washer, stick to small gears and install 180 degrees apart. Align thrust washers. Install threaded washers. Drive in shaft and secure with spring pin.
4. Press small gear outward and check play of large gear by hand. Adjust play by inserting thicker shim. See «PINION GEAR SHIM THICKNESS»(/audi/a4/b5-1994-1999/remont/differentials-drive-axles/#differential-drive-shaft) table. Maximum play should be .004" (.1 mm). NOTE: If no play can be felt, adjustment is still correct if differential gears can be turned. PINION GEAR SHIM THICKNESS Thickness In. (mm) Part Number .020 (.5) 011 519 215 .024 (.6) 088 409 249 .028 (.7) 088 409 249 A .032 (.8) 088 409 249 B .036 (.9) 088 409 249 C .040 (1.0) 088 409 249 D
5. Heat ring gear to 212°F (100°C) Install ring gear to gear housing aligning match marks. Install bolts and tighten to specification. Heat large and small tapered roller bearings to 212°F (100°C) and press on gear housing.
6. Install gear housing assembly into differential housing. Install NEW "O" ring to differential cover and install to differential housing. Tighten to specification. See «TORQUE SPECIFICATIONS»(/audi/a4/b5-1994-1999/remont/differentials-drive-axles/#differential-drive-shaft__torque-specifications) . Install axle flanges, and drive axle flange (torque tube). To install assembly, reverse removal procedure. Fill differential to specification.

Scheme 4

Disassembly & Reassembly

1. Remove bolts securing torque tube to differential. Using puller threaded into flange, remove driveshaft flange with torque tube. Using 3 arm extractor, remove sleeve. Remove transmission support. Remove snap ring. Thread M8 bolt into cap and remove cap. Expand lock ring on flange shaft and remove from groove.
2. Using puller, remove flanged shaft from torque tube. (Scheme 7) Remove end seal and lock ring. Using puller, remove flanged sha ft bearing. Press out backing plate (only if damaged).
3. Install NEW flanged shaft bearing and lock ring. Lubricate outer circumference and seal lips of oil seal with transmission fluid, and drive in seal as far as possible. Place lock ring in torque tube, Install flanged shaft into torque tube, and place lock ring in groove. Install sleeve on flanged shaft. Install cap with seal and install snap ring. Install transmission support. Install NEW "O"ring and torque tube.

Scheme 5

Scheme 6

Scheme 7

Clutch Body Shim Thickness

To determine clutch body shim thickness, measure depth "B", determine shim thickness of shim using table. See CLUTCH BODY SHIM THICKNESS table. (Scheme 8) Ensure oiling grooves on differential housing and on clutch body align.

CLUTCH BODY SHIM THICKNESS

FLANGED SHAFT SHIM THICKNESS

Scheme 8

Scheme 9

Drive Pinion & Ring Gear

1. This adjustment should only be performed if deviation "r" is not inscribed on ring gear and parts that directly affect installation position of drive pinion are to be replaced (i.e. drive pinion tapered roller bearings or final drive housing tapered roller bearings).
2. Set up Measuring Bar (VW 385/1), adjusting ring dimension "a" to 2.36" (60 mm), and movable adjusting ring dimension "b" to 1.97" (50 mm). Set up measuring bar as follows: Dial Indicator Extension (VW 385/20) should be.12" (3 mm). Set Adjustable Master Gauge (VW 385/30) to 2.09" (53.15 mm.) Zero dial indicator with preload of.12" (3 mm). (Scheme 10) 3 Install measuring bar into final drive housing and measure difference relative to R0 (reading of maximum deflection/reversal point in Red numerical range). Reading obtained corresponds to deviation "r". Note reading.

Drive Pinion

1. With differential housing mounted securely, install large outer race of tapered roller bearing into housing without shim. Install small outer tapered roller bearing race into housing. Install drive pinion. Heat roller bearing to 212°F (100°C). Install roller bearing onto drive pinion, without spacer sleeve, and press into position. Tighten drive pinion nut until reaching friction torque of 25-28 INCH lbs. (28-32 N.m).
2. Set up measuring bar. See step 2) under DRIVE PINION & RING GEAR. (Scheme 11) Attach End Gauge (VW385/33) to drive pinion head. Install Measuring Bar (VW 385/1). Install differential cover with 4 bolts. Move second centering plate to outside, by means of movable adjusting ring, so that it is just still possible to turn measuring bar (gauging drift) by hand. Measure distance "e". Turn gauging drift until dial indicator tip touches end plate on drive pinion to indicate maximum deflection (reversal point). Reading obtained is distance "e" (Red numerical range). NOTE: Remove measuring bar, ensure dial indicator is set to zero with.12" (3 mm) preload with Adjustable Master Gauge (VW 385/30) installed. If not, repeat measurement.
3. Shim S3 equals maximum deflection reading obtained "e", minus deviation "r" (indicated on ring gear in 1/100 mm or determined by actual measurement). See «SHIM S3 THICKNESS»(/audi/a4/b5-1994-1999/remont/differentials-drive-axles/#differential-drive-shaft) table for available shims. Remove measuring bar and drive pinion. Re-install drive pinion with calculated size of shim, spacer sleeve and seal. See «DIFFERENTIAL ASSEMBLY»(/audi/a4/b5-1994-1999/remont/differentials-drive-axles/#differential-drive-shaft). Rotate drive pinion in both directions several times. Install measuring bar. If correct shim was selected, dial indicator reading should be plus or minus.0016" (.04 mm) within value of inscribed deviation "r".

SHIM S3 THICKNESS

Scheme 10

Scheme 11

Differential Bearing Preload

1. If differential housing, differential cover, tapered roller bearings, or drive gear set have been replaced, differential bearing preload adjustment is necessary. Determine total shim thickness (shim S1 plus shim S2).
2. With drive pinion removed, remove seals and outer bearing races for differential tapered roller bearings and remove shims. See «DIFFERENTIAL ASSEMBLY»(/audi/a4/b5-1994-1999/remont/differentials-drive-axles/#differential-drive-shaft). Drive in bearing outer races without shims. Install differential into housing. Install cover and tighten bolts using a crisscross pattern to 18 ft. lbs. (25 N.m).
3. With cover side up, attach dial indicator to differential and zero dial (3 mm range) with preload of 1 mm. Move differential up and down (DO NOT turn differential) and note measurement. (Scheme 12)
4. Adding a constant compression value of.016" (.40 mm) to measurement noted equals total shim thickness (shim S1 plus shim S2). Install calculated total shim thickness of shim behind bearing race in final drive housing (S2). See «SHIM S2 THICKNESS»(/audi/a4/b5-1994-1999/remont/differentials-drive-axles/#differential-drive-shaft) table for available shims.
5. Measure friction torque. See «DIFFERENTIAL ASSEMBLY»(/audi/a4/b5-1994-1999/remont/differentials-drive-axles/#differential-drive-shaft). With NEW bearings, friction torque should be 23-31 INCH lbs. (25-35 N.m). With used bearings, bearings that have been run at least 30 miles, torque should be 3-5 INCH lbs. (3-6 N.m).

SHIM S2 THICKNESS

Torque Backlash

1. With drive pinion installed with shim S3 and differential total shim thickness installed on housing side, rotate differential several times in both directions to settle roller bearings. Install dial indicator with Extension (VW 392/10, 6 mm flat), Measuring Lever (VW 388) and Adapters (VW 387, VW 521/4 and VW 521/8). Set measuring lever "a" to 3.11" (79 mm). (Scheme 13)
2. Turn ring gear as far as stop, and zero dial indicator. Turn ring gear back, read and record backlash. Repeat procedure after turning ring gear 90 degrees in each case. Read and record 4 measurements. Add measurements and divide by 4 to obtain average torque backlash. See «SHIM S1 THICKNESS»(/audi/a4/b5-1994-1999/remont/differentials-drive-axles/#differential-drive-shaft) table for available shims.
3. Install calculated shims. Recheck measurements. Measure total backlash four times around circumference. Total backlash should be between.0047-.0087" (0.12-0.22 mm).

SHIM S1 THICKNESS

Scheme 12

Scheme 13

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• TROUBLE SHOOTING - BASIC PROCEDURES
• CENTER BEARING SHIM THICKNESS
• TORQUE SPECIFICATIONS
• FLUID TYPE & CAPACITY