Measuring torsional side clearance

WARNING: This page is about a different car, the 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

Pinion installed with shims "S3*" and "S4*"

Install differential with ring gear: S1* is installed on cover side, S2* in transmission housing.
Mount final drive cover and tighten bolts to 25 Nm.
Insert adjustment tool for ring gear VW 521/4 and VW 521/12.
Rotate differential 5 turns in both directions, so that tapered roller bearings slip into place.

Fig 1: Measuring Backlash

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Secure dial indicator holder VW 387 to housing.
Insert dial indicator together with dial indicator extension VW 382/10 (6 mm plane).
Set measuring lever VW 388 to dimension "a" = 67 mm (for ring gear diameter 170 mm).
Determine clearance between flanks of teeth as follows:

Rotate ring gear until it makes contact with one tooth flank (end of clearance).
Set dial indicator to "0" with 2 mm pre-load.
Turn ring gear back until it makes contact with opposite tooth flank (torsional side clearance).
Read off torsional side clearance and note down measured value.

Turn ring gear additional 90 ° turn in each direction and repeat measurement 3 times.

NOTE:

Fig 2: Installing Clamping Piece VW 386 A

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If pinion turns when differential is rotated, install VW 386 A to ensure that exact torsional side clearance can be measured.
Release clamp for turning ring gear.