Audi Workshop Service and Repair Manuals

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

t  Camshaft lock -T10016-

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 locating holes in the camshaft sprockets 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.

–  Insert locking pins -D- on camshaft lock -T10016- all the way into locating holes in camshaft housing as follows: l  Through locating hole in inlet camshaft sprocket -C-. l  Through locating hole in exhaust camshaft sprocket. l  The knobs on locking pins must be on a level -line A-. –  Push retainer -B- onto inlet camshaft sprocket as far as stop. –  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. –  Detach camshaft lock -T10016-. –  Use an Allen key to turn tensioning roller in anti-clockwise direction -arrow- and detach toothed belt.   Note t  Camshaft lock -T10016- must be fitted again if further repair work has to be performed on the cylinder head or valve gear. t  If the toothed belt is re-installed immediately, attach camshaft lock -T10016- after installing the toothed belt.

Installing l  Tightening torques → Chapter Installation is carried out in the reverse order; note the following: –  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

–  Insert locking pins -D- on camshaft lock -T10016- all the way into locating holes in camshaft housing once again.

–  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 camshaft lock -T10016-. –  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 locating holes in the camshaft sprockets must align with the corresponding holes in the camshaft housing -arrows-.

–  Check that locking pins -D- on camshaft lock -T10016- can again be inserted all the way into locating holes in camshaft housing as follows: l  Through locating hole in inlet camshaft sprocket -C-. l  Through locating hole in exhaust camshaft sprocket. –  Repeat adjustment procedure if holes do not align → Anchor. Remaining installation steps are carried out in reverse sequence; note the following: –  Install poly V-belt pulley for crankshaft → Chapter. –  Install engine mountings → Chapter.