Remove the timing cover as described above. Remove the oil thrower from the crankshaft, noting that the face marked 'F' faces outwards away from the engine. Release the tab on the camshaft lock washer, unscrew the camshaft sprocket retaining nut and remove the nut and lockwasher.
On 1275 GT models, remove the two retaining screws and detach the timing chain tensioner from the engine front plate .
Rotate the crankshaft to bring the timing marks on the crankshaft and camshaft sprockets opposite each other .
Remove both the sprockets, together with the timing chain, by easing each wheel forward a fraction at a time with suitable small levers.


If moved, turn the crankshaft to bring the keyway to the top (TDC position) and the camshaft to bring the keyway to approximately the 2 o'clock position .
Assemble the sprockets in the timing chain with their alignment marks opposite each other. Keeping the gears in this position fit the sprocket in the crankshaft then rotate the camshaft as necessary to align the key with the keyway in the sprocket. Push both gears as far onto the shafts as they will go, and secure the camshaft sprocket with the lock washer and nut.
Check the alignment of the sprockets by placing a straight-edge across the teeth of both gears and measuring the gap between the straight-edge and the crankshaft sprocket with feeler gauges. Adjust, if necessary, by altering the thickness of the shim pack behind the crankshaft sprocket. The key must be removed from the crankshaft keyway to allow the shims to be removed.
On 1275 GT models, refit the timing chain tension on the engine front plate.
Refit the oil thrower and timing cover, as detailed previously.