Removing, installing and tensioning injection pump toothed belt (engine codes AAB, AJA) — AUDI

🧭 Before you start

Fits: platform codes 70A, 70B, 70C, 70E, 70H, 70J, 70K, 70L, 70M, 7DA, 7DB, 7DC, 7DE, 7DH, 7DJ, 7DK, 7DL, 7DM

• Timing position: the crankshaft or camshaft is set and locked during this job
• Special tools named: dial gauge

Don't miss

• In vehicles 09.94 ▸, a securing bolt is located on left and right in lock carrier.
• Marks (arrows) on injection pump pulley/bracket (C) and flywheel/clutch housing (A) or drive plate/clutch housing (B) must align.
• This condition is only achieved every 2nd TDC position.
• Mark direction of rotation of toothed belt
• Hold injection pump pulley with counterhold tool3036; unscrew securing bolt and remove pulley with toothed belt

🔧 Engine codes this applies to

🔩 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. Remove noise insulation tray 50.
2. Remove radiator grille 66
3. Remove securing bolts (1) on left and right [Note: In vehicles 09.94 ▸, a securing bolt is located on left and right in lock carrier.]
4. Fold lock carrier with radiator out forwards (arrow)
5. Remove injection pump toothed belt guard

6. Turn crankshaft in engine direction of rotation to TDC No. 1 cylinder:
7. Marks (arrows) on injection pump pulley/bracket (C) and flywheel/clutch housing (A) or drive plate/clutch housing (B) must align.
8. Set TDC adjustment bar2068 A to 82 mm (arrow A), left notch of vernier scale is reference point
9. Screw in TDC adjustment bar2068 A as shown; turn crankshaft until TDC mark on flywheel/drive plate aligns with edge of TDC adjustment bar2068 A(arrow) and marks on injection pump pulley and bracket align [Note: This condition is only achieved every 2nd TDC position.]
10. Lock injection pump pulley with locking pin2064
11. Mark direction of rotation of toothed belt
12. Hold injection pump pulley with counterhold tool3036; unscrew securing bolt and remove pulley with toothed belt
13. Check whether TDC mark on flywheel and reference mark are aligned
14. Mount toothed belt for injection pump pulley with injection pump drive pulley; tighten securing bolt until drive pulley can still be turned by hand
15. Note direction of rotation with used belts.
16. Check toothed belt tension with V and toothed belt testerVW 210, scale value: 12...13
17. Adjust toothed belt tension to scale value after loosening securing bolts (arrows) and shifting bracket (with injection pump)
18. Remove locking pin2064 from injection pump pulley
19. Screw in dial gauge adapter2066 (measuring range 0...3 mm) with approx. 2.0 mm pre-tension instead of plug
20. Check that crankshaft is still positioned at TDC No. 1 cylinder, and set commencement of injection as follows: [Note: To enable the dial gauge to be read on turning the injection pump drive pulley, turning must be carried out from below with the vehicle raised.When checking the commencement of injection by turning the crankshaft back and forth, a second person must observe the marks on the flywheel/clutch housing.]
21. Turn injection pump drive pulley in engine direction of rotation -direction of arrow A- until dial gauge needle no longer moves using counterhold tool3036
22. Set dial gauge to "“0”"
23. Turn injection pump drive pulley in engine direction of rotation -direction of arrow B- until dial gauge shows: Engine code AAB 1.00 "“ 0.02 mm stroke (commencement of injection): Engine code AJA 0.90 ”" 0.02 mm stroke using counterhold tool3036.
24. Hold injection pump drive pulley in position with counterhold tool3036 and pre-tighten to 50 Nm [Note: Now, commencement of injection must be checked again by turning back the crankshaft at the vibration damper until the dial gauge shows "“0”" and turning forwards to TDC. Test value deviates from the set value due to toothed belt slip.] — 50 Nm (37 lb-ft)
25. Commencement of injection must now be corrected via adjustment for a second time with a corresponding allowance.
26. Following adjustment for the second time, hold injection pump drive pulley with counterhold tool3036 and tighten to 100 Nm — 100 Nm (74 lb-ft)
27. Install injection pump toothed belt guard
28. Install radiator with lock carrier 66
29. Install noise insulation tray 50.

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