Replacing the camshaft drive chains (Renault Espace III)

Fig. 2.9. Gas distribution mechanism:1 - crankshaft sprocket; 2 - camshaft drive chains; 3 - shoe; 4 - chain tensioner shoe; 5 - hydromechanical chain tensioner; 6 - camshaft sprocket; 7 - eccentric; 8 - Automatic tensioner for balance shaft drive chain; 9 - balance shaft drive chain; 10 - asterisk; 11 - camshafts; 12 - rocker axis; 13 - rocker arm axle support; 14 - exhaust valve rocker; 15 - intake valve rocker; 16 - spacer sleeve; 17 - exhaust valve; 18 - inlet valve; 19 - lower spring plate; 20 - valve spring. 21 - upper spring plate;22 - crackers; 23 - balancing shaft; 24 - balance beams; 25 - balance shaft support; 26 - key; 27 - retaining ring; 28 - pin "Mecanindus"; 29 - distributor drive bushing

Attention

• If one part needs to be replaced, all timing drive parts must be replaced: chains, sprockets, shoes and tensioners.
• This operation requires removal of the engine together with the gearbox.

Fig. 2.10. Location of the timing gear cover (1)

Fig. 2.11. To loosen the chain tension, turn the lock counterclockwise

Removal

• Remove the engine and gearbox from the vehicle.
• Remove the engine mount bracket mounting panel.
• Remove the thermostat housing.
• Remove the accessory drive belt pulley and take out the oil seal.
• Turn the crankshaft to a position where the accessory drive belt pulley key is vertically at the top.
• Remove the front and rear cylinder head covers.
• Remove the valve timing cover
• Remove the oil pump sprocket mounting bolts and simultaneously remove the two sprockets, chain, crankshaft spacer sleeve and key.
• Loosen the automatic chain tensioner as much as possible and use tool Mot 1209 to secure it in this position.
• Remove the bolts securing the front cylinder head camshaft sprocket and the balance shaft sprocket.
• Loosen the timing chain tensioners as much as possible and secure them in this position by turning the latches counterclockwise with a screwdriver.
• It is prohibited to remove the stopper 1 (Fig. 2.12) of the chain tensioner. The position of this stopper (active or passive) is determined by the action of the spring (2), which pushes the ball (3) into the locking channel.

Fig. 2.12. Chain tensioner stopper: 1 - stopper; 2 - spring; 3 - ball

• If the stopper was accidentally removed, the entire tensioner must be replaced, since during installation it is impossible to be sure that the stopper is correctly positioned in relation to the pressure ball (due to the danger of placing the locking channel on the spring coils).
• Remove the chain tensioners, being careful not to damage the filters located behind the tensioners
• Remove the bolt securing the rear cylinder head camshaft sprocket.
• Remove the boots from the stretched target branch
• At the same time, remove the chain and sprocket from the rear cylinder head camshaft.
• At the same time, remove the chain and 2 sprockets from the front cylinder head camshaft, being careful not to lose the key (Fig. 2.13).

Fig. 2.13. Timing mechanism drive: 1 - Chain; 2- camshaft sprocket; 3 - crankshaft; 4 - crankshaft sprocket; 5 - spacer sleeve; 6 - oil pump drive sprocket; 7 - chain guide shoe; 8 - chain tensioner; 9 - oil pump drive chain; 10 - camshaft; 11 - camshaft sprocket; 12 - camshaft fixing plate; 13 - cover gasket; 14 - front cover; 15 - front crankshaft seal ring; 16 - crankshaft pulley; 17 - protective plate

Installation

• Rotate the engine crankshaft so that the keyway on the crankshaft faces the front section of the cylinder block.
• Install the new filter and chain tensioner onto the front section of the cylinder head.
• Install key 1 sprocket onto the crankshaft.
• Install the shoe and secure it with the bolt, having previously lubricated its threads with the locking agent Loctite Frenetanche. Install the front cylinder head camshaft sprocket in the chain so that the timing mark on the front side of the sprocket is located between the two marks of the links of the chain, as shown in Figure 2.14.

Fig. 2.14. Position of the front cylinder head camshaft: 1 - crankshaft key, turned towards the front section of the block; 2- mark on the camshaft sprocket, located between the two marks on the cylinder chain

Fig. 2.15. Location of oil filters (B) of the chain tensioner

Fig. 2.16. Position of the rear cylinder head camshaft: 1 - crankshaft key, turned vertically downwards; 2 - mark on the camshaft sprocket, located between the two chain marks

Fig. 2.17. Chain and sprockets drive the oil pump

• While maintaining the chain and sprocket in this position, install the lower portion of the chain onto the crankshaft sprocket and align the single mark on the chain link with the timing mark on the front of the sprocket.
• Install the sprocket onto the front cylinder head camshaft.
• Install the shoe and secure it with the bolt, after lubricating its threads with Loctite Frenetanche locking agent.
• Turn the engine crankshaft so that the keyway on the crankshaft is vertically downwards.
• Install the new filter and chain tensioner onto the rear section of the cylinder block.
• Install the shoe and secure it with a bolt, after lubricating its threads with Loctite FrenWanche.
• Install the rear cylinder head camshaft sprocket onto the chain so that the timing mark is between the marks on the chain links. Support the chain and sprocket in this position and install the chain onto the crankshaft sprocket so that the mark on the chain link aligns with the timing mark on the crankshaft sprocket.
• Install the sprocket onto the rear cylinder head camshaft, with the protrusion on the sprocket aligning with the groove in the camshaft.
• Install the shoe and secure it with the bolt, after lubricating its threads with Loctite Frenetanche locking agent.
• Install the rear cylinder head camshaft sprocket mounting bolt and tighten it to the specified torque.
• Release the chain tensioners.
• Install the balance shaft sprocket together with the chain, ensuring that the mark on the balance shaft sprocket is aligned with the mark on the camshaft sprocket.
• Apply Loctite Frenetanche to the sprocket bolt threads and screw the bolt in.
• Remove the automatic chain tensioner locking device and check the chain tension.
• Install the spacer sleeve, key and oil pump drive sprocket onto the crankshaft.
• Install the chain and sprocket of the oil pump drive and secure with bolts, after lubricating the bolt threads with Loctite Frenetanche locking agent
• Apply a layer of sealant to the mating surface of the timing cover.
• Install the timing cover and secure with bolts, after lubricating the threads of the smaller bolts with Loctite Frenetanche locking agent
• Apply Loctite Frenetanche to the threads of the cylinder head cover bolts.
• Apply a thin layer of sealant to the mating surface of the cylinder head cover, install the cover and secure it with bolts
• Install the thermostatic body.
• Using tool Mot 658, install the oil seal into the timing cover.
• Install the accessory drive belt pulley and secure it with the nut.
• Install the engine mount bracket panel.
• Install the engine and gearbox into the vehicle.