Audi Workshop Service and Repair Manuals

Repairs after which the pinion shaft must be adjusted => table on Page 39-39.

Special tools, testers and auxiliary equipment required

• ◆ Crankshaft seal installing tool VW 204 B
• ◆ Extractor lever for gear set VW 296
• ◆ Universal measuring tool VW 385
• ◆ Universal mandrel VW 385/1
• ◆ Centring disc VW 385/2 (for gearboxes without polygon bearings)
• ◆ 2 x centring disc VW 385/3
• ◆ Measuring plunger VW 385/14
• ◆ Master gauge VW 385/30
• ◆ End measuring plate VW 385/33
• ◆ Universal dial gauge bracket VW 387
• ◆ Thrust plate VW 401

• ◆ Press tool VW 407
• ◆ Tube VW 519
• ◆ Fitting tool VW 792
• ◆ Thrust plate 3005
• ◆ Sleeve 3182
• ◆ Torque gauge 0 ... 600 Ncm
• ◆ Dial gauge
• ◆ Dial gauge extension 9.3 mm
• ◆ Dial gauge extension 6.5 mm
• ◆ Dial gauge extension 30 mm

Determining total shim thickness "Stotal" for shims "S3" + "S4"

(Setting preload of taper roller bearing for drive pinion)

• ● Differential removed.

• ‒ Press on large taper roller bearing inner race => from Page 35-23.
• ‒ → Secure lower taper roller bearing (arrow).

Note:

Illustration shows pinion shaft without gearwheels.

• ‒ → Fit taper roller bearing outer race for pinion shaft in gearbox housing without shims => Fig.35-36.

• ‒ Insert rubber washer -Item 35-33 in gearbox cover.

Thrust plates and rubber washers with different thicknesses can be installed:

• ‒ → Fit taper roller bearing outer race for pinion shaft in gearbox cover with shim "S4*" (1.0 mm thick) => Fig.35-38.

Note:

For measurement purposes a shim "S4" with a thickness of 1.0 mm is initially inserted It is referred to as "S4*" in the following. After determining measurement "e", "S4*" will be replaced by the correct shim "S4".

• ‒ Insert completely assembled pinion shaft in gearbox housing.
• ‒ Fit gearbox cover and tighten bolts to 22 Nm.

• ‒ Turn gearbox so that the gearbox cover is downwards.

• ‒ → Press down on face of pinion shaft with lever VW 296 until the taper roller bearing outer race contacts the gearbox cover.
• ‒ Maintaining pressure, turn pinion shaft by hand so that the taper roller bearing settles.

• ‒ → Assemble measuring equipment, use a 30 mm dial gauge extension.
• ‒ Set dial gauge (3 mm measuring range) to "0" with 2 mm preload.

Note:

The dial gauge extension must contact the machined surface on the face of the pinion.

• ‒ Turn gearbox 180o so that the gearbox cover is upwards.

• ‒ Rotate pinion shaft 5 turns in both directions to settle the taper roller bearing.

• ‒ → Read off play on dial gauge and note reading.
• ‒ Measurement in example: 0.45 mm

Note:

If the measurement has to be repeated, the pinion shaft must first be rotated another 5 turns in each direction to settle the taper roller bearing. Reset dial gauge to "0" with 2 mm preload.

Determining thickness of shim "S3*"

• ‒ Remove taper roller bearing outer race, fit shim "S3*" in gearbox housing and install outer race again => Fig.35-36.
• ‒ Insert completely assembled pinion shaft in gearbox housing again.
• ‒ Fit gearbox cover and tighten bolts to 22 Nm.

Checking preload of taper roller bearing for drive pinion

• ‒ Rotate pinion shaft 5 turns in both directions to settle the taper roller bearing.

Notes:

• ◆ If the pinion shaft cannot be turned by hand, screw an M10 x 20 bolt into the pinion head and turn the shaft by applying a suitable tool to the bolt.
• ◆ Remove the bolt after turning the shaft.

• ‒ → Fit measuring tools and secure with bolt (arrow) to gearbox housing.
• ‒ Fit dial gauge (3 mm measuring range) onto centre of gearbox cover and set to "0" with 2 mm preload.
• ‒ Loosen gearbox cover bolts and turn pinion shaft several times.
• ‒ If the correct shims have been selected the dial gauge will now indicate the following value:
• ‒ 0.05 ... 0.15 mm
• ‒ Retighten gearbox cover bolts to 22 Nm.
• ‒ Remove measuring tools.
• ‒ Rotate pinion shaft 5 turns in both directions to settle the taper roller bearing.

Determining measurement "e"

Note:

Measurement "e" is required to determine the final shim thickness of "S3" and "S4".

• ‒ → Set adjustment rings of universal mandrel VW 385/1 to the following measurements:
• ‒ Distance a = 35 mm
• ‒ Distance b = 75 mm

• ‒ → Assemble universal mandrel VW 385/1 as shown in the illustration:

• ‒ Set dial gauge (3 mm measuring range) to "0" with 2 mm preload.

Note:

On gearboxes with flange shafts without polygon bearings (=>from Page 00-3), use centring disc VW 385/2 instead of centring disc VW 385/3 opposite the dial gauge.

• ‒ → Place end measuring plate on face of pinion shaft.

Note:

Ensure plate contact surface fits exactly and is free of oil.

• ‒ → Remove master gauge and insert measuring mandrel in the housing.
• ‒ Dial gauge extension -A- must be fitted => table, Page 39-49
• ‒ The dial gauge faces towards the final drive cover
• ‒ Fit final drive cover and tighten 4 bolts to 22 Nm.
• ‒ Using the adjustable ring, move 2nd centring disc VW 385/3 out as far as possible so that the mandrel can still just be turned by hand.

• ‒ → Turn mandrel until the dial gauge point touches the end measuring plate on pinion shaft head, then measure maximum deflection (return point).
• ‒ Measurement in following example: "e" = 0.26 mm (in red scale on dial)

Note:

Then, (after removing universal mandrel) check again that the dial gauge, with master gauge VW 385/30 in place, indicates "0" with 2 mm preload. Otherwise correct adjustments.

Determining thickness of shim "S3"

Notes:

• ◆ The deviation "r", which is related to the master gauge "Ro" is measured for the final drive sets supplied as replacement parts and marked on the outer circumference of the crown wheel.

• ◆ If dial gauge reading is in red scale, subtract dimension "e".
• ◆ If dial gauge reading is in black scale, add dimension "e".

• ‒ Determine shim(s) as accurately as possible from table. Part numbers

=> Parts List

The following shims are available for "S3"

    1)    Using the shim tolerance variations it is possible to find the exact shim thickness required, insert two shims if necessary.

Determining thickness of shim "S4"

• ‒ Determine shim(s) as accurately as possible from table. Part numbers

=> Parts List

The following shims are available for "S4"

    1)    Using the shim tolerance variations it is possible to find the exact shim thickness required, insert two shims if necessary.

Performing check measurement

Checking dimension "r"

• ‒ Install pinion shaft with determined shims "S3" and "S4" and turn 5 turns in both directions.

• ‒ → Insert universal mandrel => "Determining measurement `e'" on Page 39-49, and perform check measurement.
• ‒ Read off dial gauge anti-clockwise (red scale).
• ‒ If the shims have been correctly selected, the deviation "r" (marked on outer circumference of crown wheel) must be shown within a tolerance of ± 0.04 mm.

Note:

Then, (after removing universal mandrel) check again that the dial gauge, with master gauge VW 385/30 or VW 385/15 in place, indicates "0" with 2 mm preload. Otherwise correct adjustments.