Page 1 of 10 Removing and installing cylinder head Removing, installing and tensioning toothed belt Special tools, workshop equipment, test and measuring appliances and auxiliary items required 3359 Locking pin 3387 Pin wrench T10050 Crankshaft stop V.A.G 1331 Torque wrench (5...50 Nm) V.A.G 1332 (40...200 Nm) Torque wrench T10008 Locking plate (only vehicles with hydraulic tensioning system) Drill bit 4 mmø (only vehicles with hydraulic belt tensioning system) T10115 Locking pin (only vehicles with friction dampened belt tensioning system) Removing Adjustment work on the toothed belt must only be done when the engine is cold. Bring lock carrier into service position: => General body repairs exterior; Repair group 50; Body front; lock carrier service position
Page 2 of 10 Remove ribbed belt => Page 13-16. Remove toothed belt guard - upper part. Remove fan from viscous coupling. Remove ribbed belt relay lever from compact bracket. Remove centre toothed belt guard. Remove vibration damper/belt pulley. Remove lower toothed belt guard. Release coolant pipes for fuel cooler from engine and pull them forwards slightly (coolant hoses remain connected). Turn crankshaft to TDC No. 1 cylinder. Turn the crankshaft until the mark on the crankshaft pulley is facing up and the arrow on the rear section of the toothed belt guard aligns with lug on the hub sender wheel - arrows-. Lock hub with mandrel 3359. To do this slide mandrel through free elongated hole on left side and into hole in cylinder head. Lock toothed belt crankshaft sprocket using crankshaft stop T10050. To do this, push crankshaft stop from the face side of the toothed belt sprocket into the sprocket's teeth. The marks on the crankshaft sprocket and the crankshaft stop must align. At the same time, the shaft of the crankshaft stop must engage in the drilling in the sealing flange. Mark D.O.R. of toothed belt. Vehicles with hydraulic tensioning system Vehicles with friction dampened tensioning system => page 15-19. Identification characteristic: with belt tensioning damper -arrow-
Page 3 of 10 Insert a hexagon key into the hexagon hole onto limit stop and press the tensioning roller anticlockwise -direction of arrow- until the toothed belt tensioning device can be locked with locking plate T10008. If the hexagon key is not inserted deeply enough there is a great danger that key will slip and round-off the hexagon drive. Loosen tensioning roller securing nut. Remove toothed belt tensioning device securing bolts -1- and take off tensioning device. Take off toothed belt. Installing
Page 4 of 10 Adjustment work on toothed belts must be performed on cold engines only. Loosen camshaft sprocket securing bolts -1-, until the camshaft sprocket can be moved within the elongated holes. Turn camshaft sprocket in elongated holes clockwise -direction of arrowonto limit stop. Now turn the eccentric clockwise carefully with pin wrench 3387 until the eccentric lug lies directly before limit stop -B-. Fit toothed belt onto camshaft sprocket, tensioning roller, crankshaft toothed belt sprocket and the water pump toothed belt sprocket last of all. Install toothed belt tensioning device. Turn eccentric anti-clockwise using pin wrench 3387 (lug of eccentric moves towards limit stop - A-), until locking plate T10008 can be pulled out easily and dimension - a- is less than 4 mm. Release force of tensioning element in clockwise direction (lug of eccentric moves toward stop -B-) until distance -a- has been attained. Specified distance -a-: 4 ± 1 mm. Distance -a- becomes smaller when the tensioning roller securing nut is tightened. Therefore adjust generously using ø 4 mm drill bit. Distance -a- may be reduced to 1
Page 5 of 10 mm if engine is at operating temperature. Hold tensioning roller in this position and tighten tensioning roller securing nut to: 20 Nm and 45 (1/8 turn further). Tighten camshaft sprocket securing bolts -1- to 25 Nm. Remove mandrel 3359 and crankshaft stop T10050. Turn crankshaft two rotations in engine D.O.R. and set again to TDC No. 1 cylinder. The stub 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 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. It is not permitted to make corrections when turning to ensure the crankshaft stop will engage. Once the crankshaft stop T10050 has engaged, check: 1.) dimension -a- is ok. and 2.) the hub can be locked with locking pin 3359. If dimension -a- is not achieved: Tension the tensioning roller again. To do this, hold tensioning roller with pin wrench 3387, loosen securing bolts and release force of tensioning device until dimension -a- is attained. Specified dimension -a-: 4 ±1 mm. Tighten securing nut again to 20 Nm and 45 (1/8 turn) further. If the hub cannot be locked: Pull the crankshaft stop pin out of the hole in the sealing flange and turn the crankshaft until the hub can be locked with the locking pin. Loosen camshaft sprocket securing bolts -1-.
Page 6 of 10 Turn crankshaft slightly against engine direction of rotation until the crankshaft stop pin is positioned just before the hole in the sealing flange -arrow-. Now turn the crankshaft in engine direction of rotation until the crankshaft stop pin engages in the sealing flange whilst turning. Tighten camshaft sprocket securing bolts to 25 Nm. Remove mandrel 3359 and crankshaft stop T10050. Turn crankshaft two rotations in engine D.O.R. until crankshaft is set to TDC No. 1 cylinder again. When doing this the stub of the crankshaft stop must engage in the sealing flange whilst turning. If the crankshaft is turned past TDC No. 1 Cyl. and the crankshaft stop 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. It is not permitted to make corrections when turning to ensure the crankshaft stop will engage. Repeat check. Vehicles with friction dampened tensioning system
Page 7 of 10 Loosen tensioning roller securing nut. Loosen camshaft sprocket securing bolts -1-, until the camshaft sprocket can be moved within the elongated holes. Turn pin wrench 3387 anticlockwise (opposite direction of arrow) until the toothed belt tensioner can be fixed in place using locking pin T10115. Now turn pin wrench clockwise in direction of arrow until stop and tighten securing nut hand-tight. Now remove toothed belt first from the coolant pump and then from the remaining sprockets. Installing Adjustment work on toothed belts must only be performed on cold engines as the indicator on the tensioning element alters depending on the engine temperature. The tensioning roller must be locked with locking pin T10115 and secured to right limit stop. Turn camshaft sprocket in elongated holes anti-clockwise -in direction of arrow- onto limit stop. Fit toothed belt to crankshaft sprocket, belt tensioner and camshaft sprocket Then fit the toothed belt on the coolant pump toothed belt sprocket.
Page 8 of 10 Ensure that tensioning roller seats correctly in rear toothed belt guard -arrow-. Loosen tensioning roller securing nut. Detension belt tensioner by turning using pin wrench in opposite direction of arrow and remove locking pin from belt tensioner. Now carefully turn the belt tensioner using pin wrench 3387 in direction of arrow until the indicator is in the middle of the gap in the base plate -arrow-. Hold tensioning roller in this position and tighten tensioning roller securing nut to: 20 Nm and 45 (1/8 turn further). Tighten camshaft sprocket securing bolts to 25 Nm. Remove mandrel 3359 and crankshaft stop T10050. Turn crankshaft two rotations in engine D.O.R. and set again to TDC No. 1 cylinder. The stub 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 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. It is not permitted to make corrections when turning to ensure the crankshaft stop will engage. Once the crankshaft stop T10050 has engaged, check whether the hub can be fixed in place using locking pin 3359. If the hub cannot be locked: Pull the crankshaft stop pin out of
Page 9 of 10 the hole in the sealing flange and turn the crankshaft until the hub can be locked with the locking pin. Loosen camshaft sprocket securing bolts -1-. Turn crankshaft slightly against engine direction of rotation until the crankshaft stop pin is positioned just before the hole in the sealing flange -arrow-. Now turn the crankshaft in engine direction of rotation until the crankshaft stop pin engages in the sealing flange whilst turning. Tighten camshaft sprocket securing bolts to 25 Nm. Remove mandrel 3359 and crankshaft stop T10050. Turn crankshaft two rotations in engine D.O.R. until crankshaft is set to TDC No. 1 cylinder again. When doing this the stub of the crankshaft stop must engage in the sealing flange whilst turning. If the crankshaft is turned past TDC No. 1 Cyl. and the crankshaft stop 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. It is not permitted to make corrections when turning to ensure the crankshaft stop will engage. Repeat check. Continuation for all vehicles Install lower toothed belt guard and vibration damper/pulley.
Page 10 of 10 Install centre toothed belt guard. Install ribbed belt tensioning element on compact bracket. Secure coolant pipes for fuel cooler and install toothed belt upper guard. Install ribbed belt => Page 13-16. Install fan for viscous coupling. Install lock carrier: => General body repairs exterior; Repair group 50; Body front; lock carrier service position Check headlight adjustment and adjust if necessary: => Maintenance booklet Warning! When doing any repair work, especially in the engine compartment, pay attention to the following due to the cramped conditions: Route all the various lines (e.g. for fuel, hydraulics, activated charcoal filter system, coolant, refrigerant, brake fluid and vacuum pipes and hoses) and electrical wiring so that the original positions are restored. Ensure sufficient clearance to all moving or hot components.