Differential, Adjusting

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Special tools and workshop equipment required

Seal Installer - Crankshaft VW204B
Bearing/Bushing Installer - Multiple Use VW295
Extension Pin - 6mm VW382/10
Measuring Set - End Gauge VW385/33
Clamping Piece VW386A
Dial Gauge Holder VW387
Measuring Lever VW388
Press Plate VW402
Press Piece - Multiple Use VW412
Crown Wheel Adjusting Tool VW521
Press Piece - Multiple Use 3005
Bearing Installer - Wheel Bearing 3345
Dial Gauge for example Dial Gauge - 0-3mm VAS6080

NOTE:

Careful adjustment of the differential is important for service life and smooth running of final drive.

An adjustment of the ring gear is necessary when the differential tapered roller bearing is replaced.
The drive pinion remains installed, for this reason the adjustment backlash must always be achieved. Otherwise the Drivetrain will be damaged!
The transmission is fastened to the assembly bracket and the clutch module with the right flange shaft is removed.

Different version tapered roller bearings for differential mounting.

The application of the new bearing (efficiency bearing) went into effect from transmission production date 08/15/2011.

Old version (standard bearing) through transmission production date 08/14/2011:

Differential with two tapered roller bearings.
This procedure adjusting the differential, is described in this information .

New version (efficiency bearing) from transmission production date 08/15/2011:

Differential with left tapered roller bearing and right angular contact ball bearing

Determine the total shim thickness "S_total " for the adjusting shims "S₁ " + "S₂ "

-- Removing the LEFT tapered roller bearing outer race from the transmission housing. Refer to Figure.

-- Drive in the new outer race for left tapered roller bearing with old shims "S₁ " in the example from 1.30 mm in the transmission housing.

Fig 1: Driving Outer Race For Tapered Roller Bearing With Shim Into Transmission Housing

Courtesy of AUDI OF AMERICA, LLC

NOTE:

For the initial measurement, install the old shim "S₁ " with a thickness in the example from 1.30 mm. This will be referred to as "S₁ *" in the following. After determining the torsional backlash, "S₁ *" is replaced by the final "S₁ ".

Transmission with right tapered roller bearing on the differential.

Fig 2: Installing Outer Race Tapered Bearing

Courtesy of AUDI OF AMERICA, LLC

-- Remove the outer race/tapered roller bearing from the final drive cover. Refer to Figure.

-- Press in new outer race for the right tapered roller bearing with old shim "S₂ " with a thickness in the example from 0.87 mm in the final drive cover. The smaller diameter of the Seal Installer - Crankshaft VW204B faces the outer race.

NOTE:

For the initial measurement, install the old shim "S₂ " with a thickness in the example of 0.87 mm. This will be referred to as "S₂ *" in the following. After determining the torsional backlash, "S₂ *" is replaced by final "S₂ ".

The total shim thickness "S₁ *" and "S₂ *" is in example 2.17 mm.

Before installing the outer race a shim must always be installed.

Transmission with right angular contact ball bearing on the differential.

Fig 3: Installing Outer Race Tapered Bearing

Courtesy of AUDI OF AMERICA, LLC

-- Install the new angular contact ball bearing outer race with the old shim "S₂ " in the final drive cover. The larger diameter of the Seal Installer - Crankshaft VW204B faces the outer race.

Continuation for all

Fig 4: Identifying Differential

Courtesy of AUDI OF AMERICA, LLC

-- Insert the differential -arrow- into the transmission housing.

CAUTION:

Danger of causing damage to the gear set.

Check the torsional backlash when removing the final drive cover. Some play must always be present.
If transmission is disassembled, the play on the gear set can be checked by turning back and forth.
If transmission is not disassembled, install the Crown Wheel Adjusting Tool VW521 and check play.

-- Fasten the final drive cover carefully with four bolts diagonally to 20 Nm.

Complete the Crown Wheel Adjusting Tool VW521 as follows:

Fig 5: Crown Wheel Adjusting Tool VW521

Courtesy of AUDI OF AMERICA, LLC

Place the Positioning Tolerance Shell VW521/13 with the smaller outer diameter -arrow- on the Ring Gear Locking Sleeve VW521/4.

-- Insert the Crown Wheel Adjusting Tool VW521 and turn the differential five turns each in both directions, so that the tapered roller bearing sets.

Fig 6: Inserting Adjusting Tool VW521/4 And VW521/13 Into Differential

Courtesy of AUDI OF AMERICA, LLC

-- Remove the Crown Wheel Adjusting Tool VW521 and install the measuring tools on the transmission housing as follows:

Fig 7: Checking Tapered Roller Bearing Pre-Load

Courtesy of AUDI OF AMERICA, LLC

-- Attach the Dial Gauge Holder VW387 to the threaded hole in the transmission housing with the bolt -A-.

-- Place the Dial Gauge Extension on the center of the Measuring Set - End Gauge VW385/33.

-- Set the Dial Gauge, for example Dial Gauge - 0-3mm VAS6080, to >>0<< with 1 mm of pretension.

-- Loosen the four bolts -arrows- diagonally one turn.

-- Read the measured value on the gauge.

Specified value: 0.10 to 0.15 for differential mounting on both sides with tapered roller bearings.
Specified value: 0.25 to 0.30 mm for left differential mounting with tapered roller bearing and the right side with angular contact ball bearing (efficiency bearing).

NOTE:

If the measure value is not obtained or no backlash is felt, then correct the thickness of the shim "S₁ " and "S₂ ".

Allocate correct adjustment shims.

Torsional Backlash, Measuring

Differential installed with shims "S₁ " and "S₂ "

-- Install the differential with ring gear: S₁ in on the cover side, S₂ is installed in the transmission housing.

-- Install the final drive cover and tighten the bolts to 20 Nm.

Complete the Crown Wheel Adjusting Tool VW521 as follows:

Fig 8: Crown Wheel Adjusting Tool VW521

Courtesy of AUDI OF AMERICA, LLC

Place the Positioning Tolerance Shell VW521/13 with the smaller outer diameter -arrow- on the Ring Gear Locking Sleeve VW521/4.

-- Insert the Ring Gear Locking Sleeve VW521/4 into the differential.

Fig 9: Inserting Adjusting Tool VW521/4 And VW521/13 Into Differential

Courtesy of AUDI OF AMERICA, LLC

-- Turn differential 5 turns in both directions so that the tapered roller bearings settle.

-- Remove bolts -A-, -B- and -arrows-, and remove the center differential housing -C-.

Fig 10: Identifying Center Differential Housing To Transmission Bolts

Courtesy of AUDI OF AMERICA, LLC

Fig 11: Securing Side Shaft

Courtesy of AUDI OF AMERICA, LLC

So the side shaft doesn't turn during the measuring, block from turning.

-- To do this, insert the Counterhold - Side Shaft T40217 in the side shaft and loosely attach to the transmission cover with M8 bolts -arrows-.

-- Insert the Toothed Belt Tensioner T10020 between the side shaft -A- and Counterhold - Side Shaft T40217

NOTE:

Do not slide the Toothed Belt Tensioner T10020 up to the spur gear -B-.

-- Tighten the bolts -arrows- to 5 Nm.

Lock the pinion on removed transmission cover:

Fig 12: Securing Pinion With Clamping Piece VW386A

Courtesy of AUDI OF AMERICA, LLC

-- So the pinion -1- does not turn while measuring, secure the pinion with the Clamping Piece VW386A.

Continuation for all

-- Attach the Dial Gauge Holder VW387 to the final drive cover -arrow-

Fig 13: Attaching Dial Gauge Holder VW387 To Final Drive Cover

Courtesy of AUDI OF AMERICA, LLC

-- Insert the Dial Gauge for example VAS6080 with Extension Pin - 6mm VW382/10 (6 mm plane).

-- Adjust the Measuring Lever VW388 to dimension "a" = 54.5 mm.

Determine the play between the tooth flanks as follows:

-- Turn ring gear until it makes contact with a tooth flank (end of backlash travel).

-- Set the dial gauge to "0" with 2 mm preload.

-- Turn ring gear back until lying against an opposite tooth flank (backlash).

-- Read the torsional backlash and write down the measured value.

-- Turn ring through 90° and repeat measurements a further 3 times. Loosen the catch to turn further. Refer to Fig 11.

Determining the average torsional backlash

-- Add the four measured values and then divide the total by 4.

Example:
	1. Measured value	0.28 mm
+	2. Measured value	0.30 mm
+	3. Measured value	0.30 mm
+	4. Measured value	0.28 mm
=	Total of the measured values	1.16 mm

Result: the average torsional backlash is 1.16 mm : 4 = 0.29 mm

Determine the thickness of the shim "S₂ "

Formula: "S₂ " = "S₂ *" - measured torsional backlash + specified torsional backlash

Example:
	Old shim "S₂ *"	1.30 mm
-	Measured average torsional backlash	0.29 mm
+	Specified torsional backlash (desired average value for the torsional backlash)	0.20 mm
=	Shim thickness "S₂ "	1.21 mm

Allocate correct adjustment shims.

Determining the thickness of the shim "S₁ "

Formula: "S₁ *" = "S_total " - "S₂ "

Example:
	Total shim thickness "S_total " for "S₁ " + "S₂ "	2.17 mm
-	Shim thickness "S₂ "	1.21 mm
=	Shim "S₁ " thickness	0.96 mm

-- Remove the old shims "S₁ *" and "S₂ *" and install new determined shims. Refer to OVERVIEW - DIFFERENTIAL .

Measurement check

Fig 14: Attaching Dial Gauge Holder VW387 To Final Drive Cover

Courtesy of AUDI OF AMERICA, LLC

-- Turn the differential 5 turns in both directions after installing the shims "S₁ " and "S₂ " so that the tapered roller bearings can settle.

-- Measure backlash on the circumference four times.

Specified value: 0.12 to 0.28 for the tapered roller bearings for differential mounting on both sides with tapered roller bearing.
Specified value: 0.12 to 0.18 mm for left differential mounting with tapered roller bearing and the right side with angular contact ball bearing (efficiency bearing).

NOTE:

If the torsional backlash is outside of the tolerance, then repeat the adjustment. Total shim thickness "S_total " may not be changed.