Dismantling and assembling gearbox housing cover, gearbox housing, selector mechanism, input shaft, output shaft (pinion shaft), differential and selector forks — AUDI

🧭 Before you start

Fits: Audi A3 (8L, 1996–2003)

• Opens: engine oil
• Special tools named: puller, feeler gauge
• Renewed: locking collar, o-ring between bevel box, drive flange cap

Don't miss

• The flange shaft (right-side)/output shaft with drive flange remains in the bevel box.
• Before lifting the locking collar, take off spring and locking pieces. Then replace locking collar on synchronising hub again, but without selector fork.
• When pulling off the gear wheel ensure that the hooks do not bend outwards, if necessary tighten screw (arrow).Check 5th gear wheel for damage after pulling off.
• Unscrew countersunk bolt (arrow) for flange shaft (left-side) (counterhold flange shaft with drift to prevent it from turning).
• Do not remove nuts (B) for output shaft bearing mounting at this stage.

🔩 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. Secure gearbox to assembly stand.
2. Turn gearbox on assembly stand with oil drain plug downwards.
3. Place used oil collection and extraction unitV.A.G 1782 below gearbox.
4. Remove oil drain plug and allow gear oil to drain off.
5. If drive flange cap is fitted, pierce a hole in centre of cap using a screwdriver and lever out cap.

6. Unscrew bolt for flange shaft (right-side)/output shaft with drive flange using hexagon keyV.A.G 1669 (counterhold with drift to prevent shaft from turning). [Note: The flange shaft (right-side)/output shaft with drive flange remains in the bevel box.]
7. Unscrew bolts securing bevel box to manual gearbox (arrows A) and (arrow B).
8. Detach bevel box from manual gearbox and remove bevel box.
9. Remove clutch release lever and release bearing .
10. Unbolt guide sleeve .
11. Unbolt cover (arrow) from gearbox housing.
12. Remove selector fork for 5th gear (arrows). [Note: Before lifting the locking collar, take off spring and locking pieces. Then replace locking collar on synchronising hub again, but without selector fork.]
13. Remove bolts (A) for synchronising hub and 5th gear wheel, to do this select 1st gear (arrows 2 and 3) and 5th gear (arrow 1).
14. Pull off synchronising hub with selector gear for 5th gear and remove needle bearing.
15. Assemble two-arm pullerKukko 20/10 with hooksMatra V170(item A) and align centrally by turning screw (arrow) to pull off 5th gear wheel.
16. Pull off gear wheel using two-arm puller; if necessary, heat gear wheel using hot air blowerV.A.G 1416 prior to pulling off. [Note: When pulling off the gear wheel ensure that the hooks do not bend outwards, if necessary tighten screw (arrow).Check 5th gear wheel for damage after pulling off.]
17. Unscrew countersunk bolt (arrow) for flange shaft (left-side) (counterhold flange shaft with drift to prevent it from turning).
18. Remove bolts (arrows) for reverse shaft support.
19. Remove selector shaft with selector mechanism cover. To do this, set selector shaft in neutral position.
20. Unscrew bolts (arrows) and pull selector shaft out of gearbox housing.
21. Remove cover plate (A) and pivot pin (B) from underside of gearbox.
22. Remove pivot pins (A) from top of gearbox.
23. Remove bolts (B) connecting gearbox housing to clutch housing near differential.
24. Unscrew bolts (A) securing gearbox housing from inside clutch housing. [Note: Do not remove nuts (B) for output shaft bearing mounting at this stage.]
25. Take off gearbox housing. [Note: If necessary, use a lever to carefully lift the gearbox housing all round and alternating between sides at the protruding flange (arrows), taking care not to damage sealing surfaces.]
26. Remove selector forks (A) together with gear selector plates.
27. Remove selector mechanism for reverse gear (B).
28. Remove nuts (B) for output shaft bearing mounting. [Note: Bolts (A) were removed at an earlier stage.]
29. Remove reverse gear (A), input shaft (B) and output shaft (C) one after the other from clutch housing.
30. Remove differential.
31. Install differential.
32. Renew seals (arrows) for output shaft bearing mounting. [Note: The illustration only shows 3 of the 4 seals.]
33. Install input shaft, output shaft and reverse shaft together.
34. Tighten nuts for output shaft bearing mounting to 25 Nm and then turn 90° further. — 25 Nm (18 lb-ft)
35. Remove locking fluid on thread in reverse shaft support (arrow) using thread tap or similar.
36. Fit reverse shaft support.
37. Install selector mechanism for reverse gear.
38. Install selector forks together with gear selector plates.
39. Fit stud M8x100 mm (item A) into reverse shaft support so that support is aligned when gearbox housing is fitted.
40. Align gear selector plates.
41. Put gearbox housing in position.
42. Install reverse shaft support (arrow) as follows:
43. Screw in bolt (a) hand-tight.
44. Then unscrew stud M8x100 mm fitted some steps earlier.
45. Screw in bolt (b) hand-tight.
46. Tighten bolt (a) to 30 Nm. — 30 Nm (22 lb-ft)
47. Tighten bolt (b) to 30 Nm. — 30 Nm (22 lb-ft)
48. Install pivot pin (arrow) for selector forks; to do this align selector mechanism using a screwdriver so that the relevant pivot pin can be inserted.
49. Install cover plate for selector shaft.
50. Move gear selector plates to neutral.
51. Engage the lug (arrow 1) into the cut-out on the gearbox housing. Position selector shaft so that selector finger (arrow 2) is engaged in selector plates.
52. Install selector mechanism cover for selector shaft.
53. Fit 5th gear wheel.
54. Drive on 5th gear wheel.
55. Press 5th gear synchro-ring against tapered seat on selector gear and measure gap (a) using a feeler gauge.
56. Install 5th speed selector gear with needle bearing.
57. Fit 5th gear synchro-ring on selector gear.
58. Assemble 5th gear synchronising hub/locking collar before installing .
59. Drive on 5th gear synchronising hub. [Note: When driving on, ensure clearance for synchro-ring.]
60. Fit securing bolts for 5th gear synchronising hub and gear wheel.

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