Removing and installing cover for self-locking centre differential — AUDI

🧭 Before you start

Fits: Audi A6 C6 (4F, 2004–2011)

• Opens: gearbox oil
• Renewed: o-ring

Don't miss

• The engine must not be run and the vehicle must not be towed without gear oil. — Release fasteners marked (1, 2) and (arrow) (if fitted) and remove noise insulation panels.
• The flexible pipe connection (de-coupling element) on the front exhaust pipe must not be bent more than 10° – otherwise it can be damaged.
• The cover is not equipped with a drain plug; drain gear oil by removing the cover.
• Renew O-ring on cover for transfer box.
• Check installation position of tongue on baffle plate (arrow) again.

🔩 Torque settings

Values can differ between engine variants — check the code stamped on your block.

ℹ️ Always cross-check the exact figure against your vehicle's factory manual before final tightening — a wrong torque can damage the engine. These values are extracted from workshop data and may not cover every variant or revision.

📋 Procedure

1. ⚠ The engine must not be run and the vehicle must not be towed without gear oil. — Release fasteners marked (1, 2) and (arrow) (if fitted) and remove noise insulation panels.
2. Disconnect exhaust system at clamp (arrow). [Note: The flexible pipe connection (de-coupling element) on the front exhaust pipe must not be bent more than 10° – otherwise it can be damaged.]
3. Unscrew bolts (arrows) at centre bracket for front exhaust pipe.
4. Tie up front exhaust pipe to side or support from below.
5. Remove bolts (arrows) at tunnel cross member.

6. Remove tunnel cross member with centre bracket for front exhaust pipe.
7. Remove tunnel cross member (1).
8. Unbolt heat shield (A) for propshaft (arrows).
9. Unscrew bolts at gearbox/propshaft flange.
10. Slide propshaft together towards rear final drive. The constant velocity joints can be moved axially.
11. Tie up propshaft to side.
12. Place used oil collection and extraction unitV.A.G 1782 below gearbox.
13. ⚠ Wear safety goggles. — Slacken and remove securing bolts for cover for self-locking centre differential in sequence (6 ... 1); allow gear oil to drain out. [Note: The cover is not equipped with a drain plug; drain gear oil by removing the cover.]
14. ⚠ Pull the cover for the self-locking centre differential carefully towards the rear off the gearbox. Take care that self-locking centre differential does not drop out of gearbox. — Secure self-locking centre differential (B) and baffle plate (A) to prevent them dropping out, or pull them off the output shaft towards the rear. [Note: Renew O-ring on cover for transfer box.]
15. Clean baffle plate, lubricate with gear oil and insert in gearbox.
16. Fit self-locking centre differential (B) onto splines of output shaft (turn slightly at the same time). [Note: Check installation position of tongue on baffle plate (arrow) again.]
17. Check that self-locking centre differential can be turned by hand when it is in position.
18. Check whether the tongue (arrow) on the baffle plate is still located properly.
19. Place cover onto self-locking centre differential with shaft installed; turn slightly if necessary.
20. Tighten bolts of cover for self-locking centre differential as follows:
21. Tighten bolts (1) and (2) to 3 Nm. — 3 Nm (2.2 lb-ft)
22. Tighten bolts (1 to 6) to 23 Nm in the sequence indicated. — 23 Nm (17 lb-ft)
23. Install propshaft Rear final drive 01R39 or Rear final drive 0AR39.
24. Install exhaust system 26.
25. Fill up gear oil in transfer box

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