Timing Belt: Service and Repair

Toothed belt, removing and installing

Tools

Special tools, testers and auxiliary items required
^ Pin 3359
^ Toothed belt tensioner T10020 or T10004
^ Pin T10115
^ Crankshaft stop T10050
^ Torque wrench V.A.G1331
^ Torque wrench V.A.G1332

Special tools, testers and auxiliary items required
^ Engine support bridge 10-222 A with Engine support feet 10-222 A /8 (modifying Adapter 10-222 A/21 )
^ Toothed belt tensioner T10020 or T10004 Counterhold T10172
^ Adapter T10172/4

Special tools, testers and auxiliary items required

^ Pin wrench 3387 (for engines with hydraulic tensioning device)

^ Marking plate T10008 (for engines with hydraulic tensioning device)

Note:
^ A new tensioning roller has been gradually introduced. The new tensioning roller has an additional hex bit - arrow -. Use a hex key to tension/loosen the toothed belt instead of the toothed belt tensioner T10020 or T10004. This does not change the work sequence.

Modifying adapter 10-222 A/21 of engine support bridge 10-222 A
The engine support bridge 10-222 A is required to support the engine/transmission assembly.

To fix engine support feet 10-222 A/8 to adapter 10-222 A/21 a new hole is required.

Dimensions given are in mm.
- Drill a hole of 12.5mm diameter - arrow - into adapter 10-222 A /21.

Removing

Note:
^ Perform toothed belt adjustment work on a cold engine only.

- Remove engine cover.
- Remove ribbed belt.
- Remove tensioning element for poly V-belt.
- Remove coolant expansion tank (coolant hoses remain connected).
- Remove retaining plate for fuel filter.

- Mount engine support bridge 10-222 A and take up weight of engine in its installed position.

- Remove securing bolts from assembly mounting/engine bracket, assembly mounting/body, assembly mounting bracket/body - arrows - and remove assembly mounting complete.

Note:
^ The engine mounting may only be removed if the engine is supported with engine support bridge 10-222 A!
^ The engine bracket must only be loosened when the engine mounting has been removed.

- Remove toothed belt guard upper part.

- Remove lower charge air pipe - 1 -. Remove bolt/screw - 2 - and release connector - arrow - to do this. Carefully cover or close open ends.
- Remove center and right noise insulation.

- Remove bolts - arrows - from engine mounting on cylinder block and remove.

Note:
^ When loosening both upper engine mounting bolts the engine must be raised slightly with the support bridge.
^ When loosening the front engine mounting bolt the engine must be raised slightly with the support bridge.

- Remove vibration damper/belt pulley.
- Remove lower and middle toothed belt guards.
- Set crankshaft to TDC No. 1 cylinder.

Note:
^ The engine may only be turned over using the crankshaft.

^ Turn the crankshaft in engine direction of rotation until the marks on the crankshaft toothed belt sprocket are at the top and arrow "4Z " - 2 - on the rear toothed belt guard is aligned behind the lugs - 1 - of the sender wheel.
^ In the illustration the camshaft toothed sprocket is shown without the toothed belt.

- Lock hub using pin 3359. To do this slide pin through free elongated hole on left hand side and into hole in cylinder head.

- Lock crankshaft toothed belt pulley using crankshaft stop T10050. To do this slide crankshaft stop into teeth of sprocket from front of sprocket.

Note:
^ Marks on crankshaft toothed belt sprocket - 2 - and on crankshaft stop - 1 - must align with one another. The pin of the crankshaft stop must then engage in the hole in the sealing flange.

- Mark direction of rotation of toothed belt.

Engines with hydraulic tensioning device

Identifying characteristics:

With tensioning element for toothed belt - arrow -.

- Insert a hex key into hex hole onto limit stop and press tensioning roller counterclockwise - direction of arrow - until toothed belt tensioning device can be locked with marking plate T10008.

Note:
^ If the hex key (Allen key) is not inserted sufficiently there is a danger that the key will slip out and cause damage.
^ The tensioning device is oil dampened and can only be moved back slowly using an even and constant pressure.

- Loosen tensioning roller securing nut.

- Remove toothed belt tensioning device securing bolts - arrows - and remove tensioning device.
- Take off toothed belt.

Engines with friction dampened tensioning device

- Loosen camshaft sprocket securing bolts - arrows - until camshaft sprocket can be moved within elongated holes.
- Loosen tensioning roller securing nut.

- Turn tensioning roller counter-clockwise with pin wrench T10020 or T10004 until toothed belt tensioning roller can be locked with pin T10115.

- Turn tensioning roller with pin wrench T10020 or T10004 clockwise onto limit stop and tighten nut - 1 - by hand.
- Remove toothed belt from coolant pump and then from remaining pulleys. Installing

Note:
^ Perform toothed belt adjustment work on cold engines only.

Engines with hydraulic tensioning device
^ Lock camshaft with pin 3359
^ Lock crankshaft with crankshaft stop T10050

- Loosen camshaft sprocket securing bolts - 1 -, until camshaft sprocket can be moved within elongated holes.
- Turn camshaft sprocket in elongated holes clockwise - direction of arrow - onto limit stop.

- Turn eccentric clockwise carefully with pin wrench 3387 until eccentric lug lies directly before limit stop - B -.
- Place toothed belt onto camshaft toothed belt pulley, tensioning roller, crankshaft toothed belt pulley and finally onto coolant pump toothed belt pulley.
- Install toothed belt tensioning device.

- Turn eccentric counter-clockwise using pin wrench 3387 (lug of eccentric moves toward limit stop - A - ), until marking plate T10008 can be pulled out easily and dimension - a - is less than 4mm.
- Move tensioning device counter force back clockwise until dimension - a - is achieved (lug of eccentric moves back toward limit stop - B - ).
- Dimension - a - : 4 ± 1 mm

Note:
^ Distance - a - becomes smaller when the tensioning roller securing nut is tightened. Therefore adjust generously using 4mm.
^ Distance - a - may be reduced to 1 mm if engine is at operating temperature.

- Hold tensioning roller in this position and tighten tensioning roller securing nut to:
- 20 Nm plus 1/8 turn (45°)

- Tighten camshaft sprocket securing bolts - 1 - to 25 Nm.
- Remove pin 3359 and crankshaft stop T10050.
- Turn crankshaft two rotations in engine direction of rotation and set again to TDC No. 1 cylinder.

Note:
^ The pin of the crankshaft stop must engage in the sealing flange when turning.
^ If the crankshaft is turned past TDC No. 1 Cyl. and the crankshaft stop pin could not engage in the sealing flange, turn the crankshaft back 1/4 turn to be able to turn the crankshaft in engine direction of rotation again to set it to TDC No. 1 Cyl. Do not make small corrections when turning to ensure the crankshaft stop pin will engage.

- Once crankshaft stop T10050 has engaged, check whether
^ Dimension - a - is achieved
^ Hub can be locked with locking pin 3359

When dimension - a - is not achieved:
- Tension tensioning roller again. Hold tensioning roller with pin wrench 3387, loosen securing nut and release counter force of tensioning device until dimension - a - is achieved.
- Dimension - a - : 4 ± 1 mm
- Tighten securing nut again to 20Nm plus 1/8 turn (45°).

If the hub will not lock:
- Pull crankshaft stop pin out of hole in sealing flange and turn crankshaft until hub can be locked with locking pin 3359.

- Loosen camshaft sprocket securing bolts - 1 -.

- Turn crankshaft slightly against engine direction of rotation until crankshaft stop pin is positioned just before hole in sealing flange - arrow -.
- Turn crankshaft in engine direction of rotation until crankshaft stop pin engages in sealing flange while turning.
- Tighten camshaft sprocket securing bolts to 25 Nm.
- Remove pin 3359 and crankshaft stop T10050.
- Turn crankshaft two rotations in engine direction of rotation until crankshaft is set to TDC No. 1 cylinder again.

Note: The pin of the crankshaft stop must engage in the sealing flange when turning. If the crankshaft is turned past TDC No. 1 Cyl. and the crankshaft stop pin could not engage in the sealing flange, turn the crankshaft back 1/4 turn to be able to turn
the crankshaft in engine direction of rotation again to set it to TDC No. 1 Cyl. Do not make small corrections when turning to ensure the crankshaft stop pin will engage.

- - Repeat check.

Engines with friction dampened tensioning device Lock camshaft with pin 3359
^ Lock crankshaft with crankshaft stop T10050
^ Tensioning roller must be installed with pin T10115 and locked.

Note:
^ The tensioning element indicator position is dependent upon the engine temperature. For this reason, perform toothed belt adjustment work on cold engines only.

- Turn camshaft sprocket in elongated holes to central position - arrow -.
- Fit toothed belt on crankshaft toothed belt sprocket, tensioning roller, camshaft sprocket, idler wheel and finally to coolant pump.

Note:
^ Ensure that tensioning roller seats correctly in rear toothed belt guard - arrow -.

- Loosen tensioning roller securing nut and pull pin T10115 off.

- Turn tensioning roller with pin wrench T10020 or T10004 clockwise until indicator aligns over lug in base plate - arrow -. Observe that securing nut does not turn.
- Hold tensioning roller in this position and tighten tensioning roller securing nut to:
- 20 Nm plus 1/8 turn (45°)

- Unlock hub with pin 3359 out of engine in direction of rotation.
- Check whether crankshaft can be locked with crankshaft stop T10050.

If the crankshaft will not lock:

- Loosen camshaft sprocket securing bolts - arrows -.

- Place counterhold T10172 with pin T10172/4 as shown. Press counterhold in - direction of arrow - and hold camshaft sprocket to pretension.
- In this position, tighten camshaft sprocket securing bolts - 1 - to 25 Nm.
- Remove pin 3359 and crankshaft stop T10050.
- Turn crankshaft two rotations in engine direction of rotation until crankshaft is set just before TDC No. 1 cylinder.
- Repeat check.

Continued for all engines
- Install middle and lower toothed belt guard.
- Install belt pulley/vibration damper.
- Tightening torque: 10 Nm plus 1/4 turn (90°)

- Fit engine mounting to cylinder block and tighten bolts - arrows -.
- Tightening torque: 45 Nm

Note:
^ Insert bolts into engine bracket before installing the bracket.
^ Before installing the assembly mounting, all engine mounting bolts must be tightened to the specified torque.

- Install engine bracket/body (replace securing bolts).
- Torque setting: 40 Nm plus 1/4 turn (90°)
- Align engine mounting Aligning engine and transmission mountings, Engine and transmission mountings, aligning.
- Tighten engine mounting to engine bracket. When doing this put contact surfaces on workbench using engine support bridge 10-222 A.
- Tightening torque: 100 Nm
- Install engine/body mounting.
- Tightening torque: 25 Nm
- Install toothed belt guard upper part.
- Install fuel filter retaining plate.
- Install coolant expansion tank.
- Install poly V-belt tensioning element.
- Tightening torque: 25 Nm
- Install Poly V-belt.
- Install engine cover.
- Install center and right side sound insulation.
- Install lower charge air pipe.