Toothed Belt, Removing, Installing and Tensioning

Toothed Belt, Removing, Installing and Tensioning

Special tools, testers and auxiliary items required

• Securing pin (3359)

• Crankshaft stop (T10050)

• Counter-holder tool (T10172)

• Special wrench, long reach (T10264)

• Locking tool (T10265)

• Torque Wrench (V.A.G 1331)

• Torque Wrench (V.A.G 1332)

• Refer to --> [ Toothed Belt Drive Assembly Overview ] Toothed Belt Drive Assembly Overview.

Removing

• Ignition switched off.

• Engine must be cold.

• Adjustments to toothed belt may generally only be performed when the engine is cold, because the indicator position of the tensioning element changes depending on engine temperature.

• The engine bracket must be removed to removing and install the tensioning roller. Refer to --> [ Engine Bracket ] Service and Repair.

Procedure

- Remove engine cover. Refer to --> [ Engine Cover ] Engine Cover.

- Remove fuel filter. Refer to --> [ Fuel Filter ] Fuel Filter.

- Remove auxiliary fuel pump. Refer to --> [ Auxiliary Fuel Pump ] Auxiliary Fuel Pump.

- Remove connector - 1 - from engine coolant temperature sensor on radiator (G83), open clips - arrows - and remove upper section of the toothed belt guard.





- Remove right front wheel housing liner.

- Remove ribbed belt. Refer to --> [ Ribbed Belt ] Ribbed Belt

- Remove belt pulley/vibration damper. Refer to --> [ 29 Belt Pulley/Vibration Damper ] Toothed Belt Drive Assembly Overview.

- Remove lower and center sections of the toothed belt guard - arrows -.





- Remove coolant pipe nut - 1 -.

- Rotate engine to TDC and secure the crankshaft toothed belt sprocket with the crankshaft stop (T10050). Push crankshaft stop from the front side of the toothed belt sprocket into the teeth. The camshaft toothed segment must be in the "12 o'clock" position.





• The markings on the crankshaft toothed belt sprocket - 2 - and the crankshaft stop (T10050) - 1 - must align. The pin on the crankshaft stop (T10050) must engage in the hole on the sealing flange.

- Mark rotational direction of toothed belt.

- Loosen bolts - 1 - of the camshaft sprocket.





- Loosen coolant pipe bolt - 1 - and then the bolts for the high pressure fuel pump toothed belt sprocket - 2 -.





- Loosen tensioning roller nut - 1 - and rotate the eccentric pulley counterclockwise - arrow - with the special wrench, long reach (T10264) until the tensioning roller can be secured with locking tool (T10265).





- Now turn tensioning roller eccentric pulley clockwise - arrow - all the way and tighten the nut - 1 - by hand.





- First remove the toothed belt from the idler pulley and then from the remaining sprockets.

Installing and tensioning

• Ignition switched off.

• Engine must be cold.

• The locking tool (T10265) must be inserted in the tensioning roller and the roller must be secured on the right stop.

• Secure crankshaft with crankshaft stop (T10050).

• Adjustments to toothed belt may generally only be performed when the engine is cold, because the indicator position of the tensioning element changes depending on engine temperature.

• The engine bracket must be removed to removing and install the tensioning roller. Refer to --> [ Engine Bracket ] Service and Repair.

Procedure

- Rotate camshaft hub with the counterhold tool (T10172) and adapters (T10172/4) until it can be secured in place. Use at least one bolt - 1 - tightened by hand to do that.





- Secure camshaft hub with the rig pin (3359). To do this, push the rig pin through the empty outer slot and into the cylinder head bore.

- Loosen bolts - 1 - that were tightened by hand.

- If necessary, rotate the high pressure fuel pump hub with a screwdriver at the bolt heads - 1 - until it can be secured.





- Secure high pressure fuel pump hub with rig pin (3359). To do that, slide the rig pin (3359) into the hole outside the toothed belt sprocket.





- Rotate camshaft sprocket and high pressure fuel pump toothed belt sprocket clockwise in their slots as far as the stop.

- Lay the toothed belt on the crankshaft sprocket, tensioning roller, camshaft sprocket, coolant pump toothed belt sprocket and high pressure fuel pump toothed belt sprocket.

- Lay toothed belt on the tensioning roller last.

- Loosen tensioning roller nut and remove the locking pin (T10265).

• Make sure the tensioning roller is properly positioned in the rear toothed belt guard - arrow -.





- Carefully rotate tensioning roller eccentric pulley clockwise with the special wrench, long reach (T10264) until the indicator is centered in the base plate gap - 2 -.





• Make sure nut - 1 - does not rotate with it.

- Hold tensioning roller in this position and tighten nut on it.

• Tightening specifications, refer to --> [ item 6, 20 Nm plus an additional / turn (45°) ] Toothed Belt Drive Assembly Overview.

- Position counterhold tool (T10172) as illustrated. Push the counterholder (T10172) in direction of - arrow - and hold the camshaft sprocket pretensioned.





- In this position, tighten bolts - 1 - for the camshaft sprocket and high pressure fuel pump toothed belt sprocket.

• Tightening specification: 20 Nm.

- Remove rig pin (3359) and crankshaft stop (T10050).

- Rotate the crankshaft at least two rotations in direction of engine rotation and position it just before cylinder 1 TDC.

- Position crankshaft stop (T10050) on the crankshaft sprocket again.

- Now rotate crankshaft in the direction of engine rotation until the crankshaft stop tab - arrow - engages the sealing flange.





• In the following check, only the camshaft and crankshaft are secured. It is difficult to find the securing point on the high pressure fuel pump hub. A small deviation - arrow - does not affect engine operation.





- Check if:

• Camshaft hub can be secured with the rig pin (3359) and

• Tensioning roller indicator is centered with or a maximum of 5 mm to the right of the base plate gap.

If the camshaft hub cannot be secured:

- Pull crankshaft stop (T10050) back until the tab is released from the hole.

- Rotate crankshaft opposite the direction of engine rotation until it is slightly past TDC.

- Now rotate crankshaft slowly in the direction of engine rotation until the camshaft hub can be secured.

- After securing, loosen the bolts on the camshaft toothed belt sprocket.

If the crankshaft stop (T10050) tab is to the left of the hole:

- Rotate crankshaft in the direction of engine rotation until the crankshaft stop tab engages the sealing flange.





- Tighten the bolts on the camshaft toothed belt sprocket.

• Tightening specification: 20 Nm.

If crankshaft stop (T10050) tab is to the right of the hole:

- Rotate crankshaft slightly opposite the direction of engine rotation.

- Now turn crankshaft in engine running direction until the crankshaft stop tab engages the sealing flange.

- Tighten bolts on the camshaft toothed belt sprocket.

• Tightening specification: 20 Nm.

Continued

- Remove rig pin (3359) and the crankshaft stop (T10050).

- Rotate crankshaft at least two rotations in the direction of engine rotation and position it just before cylinder 1 TDC.

- Check again.

If the camshaft hub can now be secured

- Tighten bolts as follows:

• Camshaft toothed belt sprocket: 1/8 additional turn (45°) further Counterhold with the counterhold tool (T10172) and adapters (T10172/4).

• High pressure fuel pump toothed belt sprocket: 1/ 4 additional turn (90°) further. Counterhold with counterhold tool (T10172) and adapters (T10172/8).





- Install lower and center sections of the toothed belt guard - arrows -.





• Tightening specifications, refer to --> [ item 27, 10 Nm ] Toothed Belt Drive Assembly Overview.

- Install belt pulley/vibration damper.

• Tightening specifications, refer to --> [ item 28, 10 Nm plus an additional / turn (90°) ] Toothed Belt Drive Assembly Overview.

- Install ribbed belt. Refer to --> [ Ribbed Belt ] Ribbed Belt.

- Install upper section of the toothed belt guard.

- Make sure the upper toothed belt guard section is clipped to the cylinder head cover correctly.





• The illustration shows the camshaft sprocket removed.

- Press upper section of the toothed belt guard in the area with the clips - arrows - against the cylinder head cover until the clips engage with each other. Use a screwdriver to press the guard if necessary.

- Check clearance between the hub and upper section of the toothed belt guard.

- Install right front wheel housing liner.

- Install insulation pan..

The rest of the assembly is basically a reverse of the disassembling sequence. When doing this note the following:

• Route fuel hoses kink-free.

• Ensure fuel hoses are seated securely.

• Do not interchange the supply and return lines (the return line is blue or has a blue marking, the supply line is white or has a white marking).

• Clip fuel hoses into the retainers.

- Install auxiliary fuel pump. Refer to --> [ Auxiliary Fuel Pump ] Auxiliary Fuel Pump.

- Install fuel filter. Refer to --> [ Fuel Filter ] Fuel Filter.

- Install engine cover. Refer to --> [ Engine Cover ] Engine Cover.