Camshaft cover and engine cover components (Engine - Td5) (page 3 of 3)

Tensioner adjuster

1 Oil supply hole 2 Tensioner adjuster body 3 Tensioner adjuster plunger 4 Sealing ring

The tensioner adjuster is hydraulically operated, oil enters the adjuster from the pressurised oil supply flowing through the cylinder head to operate a plunger which pushes against a pivoting plastic tensioner arm. The lateral movement in the tensioner arm causes the timing chain to tension and consequently compensation for chain flutter and timing chain wear is automatically controlled. The adjuster is located at the front right hand side of the cylinder head, just above the timing chain cover and below the vacuum pump oil feed port. The adjuster body is threaded and screws into a tapping in the cylinder head. Holes are contained in the adjuster body to receive oil from the cylinder head galleries, the oil pressure is used to force the plunger out of the adjuster body to press the tensioner arm against the timing chain and so using the oil trapped in the adjuster body to perform as a damper.

The internal damping of the hydraulic tensioner is tuned for each application. This means that pre EU3 and EU3 components are not interchangeable.

Drive train sprockets The camshaft sprocket has a double row of teeth which locate with the duplex timing chain. The sprocket is fitted to the camshaft by three bolts.

The oil pump sprocket is located on the front of the oil pump housing by a single retaining bolt. The sprocket has a single row of teeth which locates on the oil pump chain.

The crankshaft sprocket contains three rows of teeth, the rear row locates on the single oil pump chain and the front two rows locate with the duplex timing chain. The crankshaft sprocket has a slot in its internal diameter which locates with the Woodruff key on the crankshaft. The front of the crankshaft sprocket has a timing mark.

As a consequence of thicker chain links being used on EU3 models, the thickness of the camshaft and crankshaft sprocket teeth has been reduced. Individual pre EU3 and EU3 components are therefore not interchangeable.