Audi Workshop Service and Repair Manuals

Removing and installing main drive toothed belt Special tools and workshop equipment required

t  Locking pin -T10074-

t  Locating flange -T10110-

Removing –  Detach bonnet → Chapter. –  Remove poly V-belt → Chapter. –  Release retaining clips -arrows- and detach cover (top) for toothed belt.

–  Rotate crankshaft in normal direction of rotation to „TDC“. l  Notch on crankshaft pulley must align with edge of marking -O-.

l  The locking pin holes in the inlet camshaft sprocket with camshaft adjuster and in the exhaust camshaft sprocket must align with the corresponding holes in the camshaft housing -arrows-.   Note If the locating holes are positioned on the opposite side, the crankshaft must be turned one revolution further.

–  Lock camshafts using locking pins -T10074-: l  It should be possible to insert locking pin -A- through locking pin hole in inlet camshaft sprocket into corresponding hole in camshaft housing. l  It should be possible to insert locking pin -B- through locking pin hole in exhaust camshaft sprocket into corresponding hole in camshaft housing. –  Remove engine mounting → Chapter.   Caution Risk of damage to engine. t  To prevent the crankshaft sprocket from slipping off the drive lug, do not rotate the crankshaft after the poly V-belt pulley has been detached. t  Secure crankshaft sprocket with bolt and 2 washers before turning crankshaft. –  Remove poly V-belt pulley for crankshaft → Chapter.

–  Remove bolts -arrows- and loosen retaining clips -1- to detach toothed belt cover (bottom).

–  Remove bolts -arrows- and detach engine support -1-.

–  Check „TDC“ position of crankshaft: l  The flat tooth on crankshaft sprocket -1- must align with marking -arrow- on oil pump housing.   Note Disregard item -2-.

Caution If a used belt runs in the opposite direction when it is refitted, this can cause breakage. Before removing, mark direction of rotation of toothed belt with chalk or felt-tipped pen for re-installation. –  Loosen bolt -1- for main drive tensioning roller. –  Use an Allen key to turn tensioning roller in anti-clockwise direction -arrow- and detach toothed belt.

Installing l  Tightening torques → Chapter Installation is carried out in the reverse order; note the following: l  Inlet camshaft sprocket with camshaft adjuster and exhaust camshaft are locked with locking pins -T10074-.

–  Install tensioning roller for main drive (if removed) and turn anti-clockwise to position shown -arrow- using Allen key.

–  Tighten bolt for main drive tensioning roller hand-tight. l  Bolt -2- for oil pump housing must engage in the recess in base plate -1-.   Note Disregard items marked -3- and -arrows-.   Note

Note the marking for direction of rotation when reinstalling a used toothed belt. –  Fit main drive toothed belt -B- in the sequence coolant pump, tensioning roller, crankshaft and inlet camshaft. A -  Coupling drive toothed belt

–  To tension toothed belt, turn tensioning roller in clockwise direction -arrow A- until indicator -3- aligns with notch -arrow B- in base plate -1-. –  Tighten bolt for main drive tensioning roller. –  Remove locking pins -T10074-. –  Turn crankshaft 2 revolutions in direction of engine rotation and set to „TDC“ once again.

–  Check „TDC“ position of crankshaft: l  The flat tooth on crankshaft sprocket -1- must align with marking -arrow- on oil pump housing.   Note Disregard item -2-.

l  The locking pin holes in the inlet camshaft sprocket with camshaft adjuster and in the exhaust camshaft sprocket must align with the corresponding holes in the camshaft housing -arrows-.

–  Lock camshafts using locking pins -T10074-: l  It should be possible to insert locking pin -A- through locking pin hole in inlet camshaft sprocket into corresponding hole in camshaft housing. l  It should be possible to insert locking pin -B- through locking pin hole in exhaust camshaft sprocket into corresponding hole in camshaft housing.

–  Attach locating flange -T10110- to camshaft housing of inlet camshaft working from side facing gearbox as follows: l  The pin -arrow- on the locating flange -T10110- must engage in the small hole on the axial bearing of the inlet camshaft. l  The lugs -1- on the inlet camshaft must engage in the slot -2- in the locating flange -T10110-.

–  Turn inlet camshaft at hexagon of locating flange -T10110- in opposite direction of engine rotation as far as stop and hold in position. l  If the valve timing is correct, the holes -arrows- in the locating flange -T10110- must align with the tapped holes in the camshaft housing. –  Repeat adjustment procedure if holes do not align → Anchor. Remaining installation steps are carried out in reverse sequence; note the following: –  Install engine support and engine mounting → Chapter. –  Install poly V-belt pulley for crankshaft → Chapter.