Camshaft Timing Chain

Two, endless, simplex roller timing chains are used to drive the camshafts; one chain for each cylinder bank. The timing chains are driven from a crankshaft sprocket and are passed over two sprockets which are integral with the VCT actuators.

A procedure is required to ensure that the correct crankshaft to camshaft timing is achieved. Refer Engine - V6 3.0L SC Petrol - Removal and Installation for procedure.

Each timing chain has a fixed timing chain guide which is secured to the cylinder block with three shoulder bolts. A tensioner arm is fitted to each timing chain which can rotate around a shoulder pivot bolt. Each timing chain has a mechanical tensioner operated by spring tension to apply a controlled tension to the timing chain. This maintains the timing chain at the correct tension and allows for and dampens backlash in the chain tension due to engine deceleration. The timing chains and tensioners are maintenance free components.

Each timing chain tensioner has a hole which allow for the locking of the tensioner to facilitate removal of the tensioner arm, guide or camshaft timing chain. The tensioner plunger can be pushed back into the housing and a pin inserted to lock the tensioner in the retracted position.

The timing chains are lubricated with engine oil from jets located at the front of the engine block.