Audi Workshop Service and Repair Manuals

Adjusting pinion shaft   Note The pinion shaft only needs to be re-adjusted according to the following instructions if the final drive gear set, the tapered roller bearings for the pinion shaft or the gearbox housing are being renewed. Table of adjustments → Anchor.

Special tools and workshop equipment required

t	Drift -VW 295-

t	Measuring tool -VW 382-

t	Universal measuring tool -VW 385-

t	Universal dial gauge bracket -VW 387-

t	Measuring lever -VW 388-

t	Thrust plate -VW 402-

t	Press tool -VW 408 A-

t	Removal and installing tool -VW 459-

t	Crown wheel adjusting tool -VW 521-

t	Clamp -VW 548-

t	Press tool -VW 554-

t	Thrust plate -30-205-

t	Mandrel -30-505-

t	Thrust plate -3005-

t	Thrust pad -3062-

t	Torque gauge 0 ... 600 Ncm

t	Dial gauge

t	Dial gauge extension, 30 mm

Determining total shim thickness “Stotal” for shims “S3”  + “S4” (Setting preload of tapered roller bearings for pinion shaft) l  Differential removed. –  Fit tapered roller bearing outer race for pinion shaft into gearbox housing (without shims) → Fig. and → Fig..

–  Fit tapered roller bearing outer race for pinion shaft into bearing plate (use shim “S4*” with thickness 1.0 mm).   Note For measurement purposes a shim “S4” of 1.0 mm is fitted provisionally. It is referred to below as “S4*”. When measurement “e” has been determined, the correct shim “S4” with the final thickness will be installed in place of “S4*”. –  Insert assembled pinion shaft in gearbox housing. –  Fit bearing plate with dowel sleeves and tighten bolts to 25 Nm. –  Prior to each measurement, give pinion shaft 5 turns in each direction so that tapered roller bearings settle.

–  Set up dial gauge with 30 mm dial gauge extension. –  Set dial gauge (3 mm measuring range) to “0” with 2 mm preload. l  Tip of dial gauge must be applied to centre of pinion shaft. –  Lift pinion shaft, without turning, and read off play on dial gauge (example: 0.90 mm).   Note If the measuring procedure needs to be repeated, the pinion shaft must first be rotated 5 turns in each direction again so that the tapered roller bearing seats properly. Preload dial gauge to 2 mm and set to “0” again. The specified bearing preload is obtained by adding a constant preload figure (0.15 mm) to the measured value obtained (0.90 mm) and the thickness of the shim installed “S4*” (1.00 mm).    Formula: “Stotal” = “S4*” + measured value + bearing preload

Example:
Inserted shim “S4*”	1.00 mm
Dial gauge reading (example)	+ 0.90 mm
Preload (constant value)	+ 0.15 mm
Total shim thickness “Stotal” for “S3” + “S4”	= 2.05 mm

Determining thickness of provisional shim “S3*”    Formula: “S3*” = “Stotal” – “S4*”

Example:
Total shim thickness “Stotal” for “S3” + “S4”	2.05 mm
Inserted shim “S4*”	– 1.00 mm
Thickness of shim “S3*”	= 1.05 mm

–  Remove outer race for tapered roller bearing, insert shim “S3*” into gearbox housing and install outer race again → Fig. and → Fig.. –  Insert completely assembled pinion shaft into gearbox housing again. –  Fit bearing plate with dowel sleeves and tighten bolts to 25 Nm. –  Rotate pinion shaft 5 turns in each direction so that the bearing settles.

Determining dimension “e”   Note Dimension “e” is required to determine the final shim thickness of “S3” and “S4”. –  Set adjustment rings of universal measuring tool -VW 385/1- to the following measurements: l  Dimension -a- = 65 mm l  Dimension -b- = 65 mm.

–  Assemble universal measuring tool -VW 385/1- with dial gauge extension -VW 385/15-, length 9.3 mm and master gauge -VW 385/30- as shown in illustration. –  Set master gauge -VW 385/30- to Ro = 59.65 mm and fit onto measuring tool. –  Set dial gauge (3 mm measuring range) to “0” with 2 mm preload.   Note The gauge -VW 385/27- can also be used in place of the master gauge -VW 385/30- (Ro = 59.65 mm).

Arrangement of measuring tools when determining dimension “e” –  Place end measuring plate -VW 385/17- on face of pinion gear. l  Ensure plate contact surface fits exactly and is free of oil. –  Remove master gauge from measuring tool. –  Insert measuring tool into gearbox housing. l  The centring disc -VW 385/3- faces towards cover for final drive. –  Fit cover for final drive and tighten 4 bolts to 25 Nm. –  Using the adjustable ring, pull 2nd centring disc -VW 385/2- out as far as possible so that the measuring tool can still just be turned by hand.

–  Turn measuring tool until tip of dial gauge touches end measuring plate on face of pinion gear, and measure maximum deflection (return point). l  Measurement in following example: “e” = 0.16 mm (in red scale). Determining thickness of shim “S3”    Formula: “S3” = “S3*” + “r” + “e” (“e” in black scale) or    “S3” = “S3*” + “r” – “e” (“e” in red scale)   Note t  The deviation (tolerance) “r” in relation to the master gauge “Ro” is measured for the final drive gear sets supplied as replacement parts and marked on the outer circumference of the crown wheel. t  Subtract value “e” if measurement is obtained on red scale. t  Add value “e” if measurement is obtained on black scale.

Example:
Inserted shim “S3*”	1.05 mm
Deviation “r”	+ 0.38 mm
Determined value “e” (in red scale)	– 0.16 mm
Thickness of shim “S3”	= 1.27 mm

–  Select thickness of required shim(s) from following table:

Available shims - Thickness of shims in mm 1)2)
0.45	0.60	0.75
0.50	0.65
0.55	0.70
l  1) Part numbers → Parts catalogue. l  2) The exact shim thickness required can be obtained by using the shim tolerance variations. Install two shims if necessary.

Determining thickness of shim “S4”    Formula: “S4” = “Stotal” – “S3”

Example:
Total shim thickness “Stotal” for “S3” + “S4”	2.05 mm
Thickness of shim “S3”	– 1.27 mm
Thickness of shim “S4”	= 0.78 mm

–  Select thickness of required shim(s) from following table:

Available shims - Thickness of shims in mm 1)2)
0.45	0.65	0.85
0.50	0.70	0.90
0.55	0.75
0.60	0.80
l  1) Part numbers → Parts catalogue. l  2) The exact shim thickness required can be obtained by using the shim tolerance variations. Install two shims if necessary.

Checking dimension “r” –  Install pinion shaft with determined shims “S3” and“S4” and turn 5 turns in both directions. –  Insert universal measuring tool as described in “determining dimension 'e'” → Anchor and perform check measurement. –  Read off dial gauge anti-clockwise (red scale). l  If the shims have been correctly selected, the deviation “r” (marked on outer circumference of crown wheel) should be indicated within a tolerance of ± 0.04 mm.   Note After removing universal measuring tool, check once again that the dial gauge reads “0” with 2 mm preload when master gauge -VW 385/30- is in place. If this is not the case, correct the adjustment.

Measuring friction torque (for checking adjustment)   Note t  Tapered roller bearings for pinion shaft are of low-friction design. Friction torque can therefore only be used to a limited extent to check adjustment. Correct adjustment can only be obtained by determining total shim thickness “Stotal”. t  Do not use additional lubricant on new tapered roller bearings for friction torque measurement. The bearings have already been treated with special oil by the manufacturer.

–  Fit torque gauge 0 ... 600 Ncm -A- onto pinion shaft. B -  Socket –  Insert clamping sleeve -3116-. Friction torque specifications: l  New bearings: 80 ... 150 Ncm. l  Used bearings: 30 ... 60 Ncm.