Audi Workshop Service and Repair Manuals

Adjusting pinion shaft (Adjusting pinion shaft and hollow shaft) It is only necessary to readjust the pinion shaft when the following components have been renewed: t  Final drive gear set t  Tapered roller bearings for pinion shaft t  Gearbox housing Table of adjustments → Anchor

Special tools and workshop equipment required

t	Universal measuring tool -VW 385-

t	Universal dial gauge bracket -VW 387-

t	Thrust plate -VW 402-

t	Press tool -VW 407-

t	Multi-purpose tool -VW 771-

t	Thrust pad -3062-

t  Pin -3114/2-

t  Clamping sleeve -3116- t  Torque gauge 0 ... 600 Ncm t  Dial gauge t  Dial gauge extension, 6.5 mm t  Dial gauge extension, 30 mm

Determining total shim thickness “Stotal” for shims “S3”  + “S4” (Adjustment of pre-load of tapered roller bearings for pinion shaft with hollow shaft) l  Differential removed. –  Clamp pinion shaft in a vice using clamps -A-. –  Insert taper rollers with grease, assemble pinion shaft and hollow shaft. –  Rotate hollow shaft against pinion shaft 5 turns in both directions to settle tapered roller bearing. –  Preload pinion shaft with hollow shaft to 10 Nm, hold hollow shaft when doing this. –  Fit tapered roller bearing outer race for pinion shaft in gearbox housing without shims → Fig. and → Fig..

–  Fit outer race for tapered roller bearing for pinion shaft with shim “S4*” (1.0 mm thick) in intermediate housing.   Note For measurement purposes a shim “S4” of 1.0 mm is fitted provisionally. This 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 completely assembled pinion shaft in gearbox housing. –  Fit intermediate housing with dowel sleeves and tighten bolts to 25 Nm. –  Turn pinion shaft with hollow shaft eight turns in both directions so that the tapered roller bearings settle.

–  Set up measuring tools as shown in the illustration. –  Apply dial gauge extension (30 mm) at centre of measuring plate -VW 387/17-. –  Set dial gauge (3 mm measuring range) to “0” with a preload of 2 mm. 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. l  Measurement in example: 0.90 mm.   Note If the measurement has to be repeated, the pinion shaft with hollow shaft must first be rotated another 8 turns in each direction to settle the tapered roller bearings. Preload dial gauge to 2 mm and set to “0” again.    Formula: “Stotal” = “S4*” + measured value + bearing preload

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

Determining thickness of 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 assembled pinion shaft back in gearbox housing. –  Fit intermediate housing with dowel sleeves and tighten bolts to 25 Nm. –  Turn pinion shaft with hollow shaft eight turns in both directions so that the tapered roller bearings settle.

Determining dimension “e”   Note Dimension “e” is required to determine the final shim thickness of “S3” and “S4”. –  Adjust setting ring of universal measuring tool -VW 385/1- as follows: l  Dimension -a- = 65 mm –  Set adjustable ring as follows: l  Dimension -b- = 55 mm.

–  Assemble universal measuring tool -VW 385/1- as illustrated: t  Dial gauge extension -VW 385/15-, 9.3 mm long t  Master gauge -VW 385/30- –  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 a preload of 2 mm.   Note The gauge -VW 385/27- can also be used in place of the master gauge -VW 385/30- (Ro = 59.65 mm).

–  Set up measuring tools as shown in the illustration. –  Place end measuring plate -VW 385/17- on pinion gear. l  Ensure plate contact surface fits exactly and is free of oil. –  Remove master gauge and 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 dial gauge extension contacts end measuring plate and gauge indicates 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 allowance “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
Allowance “r” marked on crown wheel	+ 0.35 mm
Measured value “e” (in red scale)	– 0.16 mm
Thickness of shim “S3”	= 1.24 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	0.80
0.55	0.70	0.85
l  1) For Part Nos. refer to → Electronic parts catalogue l  2) Different shim thicknesses make it possible to obtain the exact shim thickness required, if necessary, fit 2 shims.

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

Example:
Total shim thickness “Stotal” for “S3” + “S4”	2.05 mm
Thickness of shim “S3”	– 1.24 mm
Thickness of shim “S4”	= 0.81 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	1.25
0.55	0.75
0.60	0.80
l  1) For Part Nos. refer to → Electronic parts catalogue l  2) Different shim thicknesses make it possible to obtain the exact shim thickness required, if necessary, fit 2 shims.

Checking allowance “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 allowance “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  The tapered roller bearings for the pinion shaft/hollow shaft are low-friction bearings. The friction torque therefore only has limited use as a means of checking the adjustment. Correct adjustment can only be obtained by determining the 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 -item 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 (used for min. 50 km).