A key locates the two drive sprockets on the
crankshaft. The crankshaft's torsional vibration
damper retains the sprockets in position.
The variable valve timing units and the exhaust
camshaft sprockets are non-interference, non-
keyed fits on their respective camshafts; the
drive being transmitted by the face to face
friction load produced by the valve timing
unit/sprocket securing bolt.
Each chain has an hydraulic tensioner operated
by engine oil. A jet of oil from the end of each
tensioner lubricates the chains. The primary chain
tensioners act on pivoting flexible tensioner
blades. The secondary chain tensioners act
directly on the chains. Guide rails are installed on
the drive side of the primary chains.
The aluminum alloy timing cover accommodates
the crankshaft front oil seal (a PTFE lip seal) and
the two variable valve timing solenoids. Silicon
rubber in-groove gaskets seal the joint between
the timing cover and the front face of the engine.
Timing Gear (Continued)