Note: To perform the work described below, you will need the following special tools: a puller designed for the torsional vibration damper (for removing the crankshaft pulley), a tool for cutting sealant pads.
Removal
1. Disconnect the negative cable from the battery.
2. Drain the cooling system, remove the radiator and fan.
3. Loosen the clamps and disconnect the bypass and lower heating hoses from the timing cover (timing chain cover).
4. Remove the drive belts from the pulleys of the steering pump, generator and (if provided) air conditioner compressor.
5. Loosen the mounting bolts, remove the steering pump and, without disconnecting the hoses, move it to the side, freeing up the working space.
6. On models with air conditioning, loosen the nuts and bolts securing the compressor to the bracket, remove the compressor and secure it to the left fender splash guard. Loosen the mounting bolts and remove the compressor bracket from the engine.
7. Remove the distributor cap and, by turning the engine in the direction of normal rotation, ensure that the rotor turns toward the location of the spark plug wire segment of the first cylinder in the distributor cap. At the same time, the distributor mark on the crankshaft pulley should align with the TDC mark on the timing chain cover scale. The engine is now in the TDC position of the end of the compression stroke of the first cylinder.
8. Remove the distributor from the engine.
9. Loosen the crankshaft pulley mounting bolt (see accompanying illustration). You can prevent the pulley from turning by wrapping the drive belt around it and tightening it with a lever. Remove the large washer from the bolt and screw the bolt back into the end of the shaft journal to prevent damage to the latter with the puller.
1 - timing chain cover; 2 - water pump; 3 - oil seal; 4 - distribution scale; 5 - distribution mark; 6 - crankshaft pulley; 7 - washer; 8 - bolt
10. Using a puller, remove the crankshaft pulley.
11. Drain the engine oil and remove the oil pan.
Note: If the oil pan is sealed to the crankcase with a gasket instead of sealant, simply tilting the front part of the oil pan will be enough to remove the timing chain cover.
Information obtained from the website NissanBook.ru
12. Loosen the front cylinder head bolts and timing chain cover bolts and carefully remove the cover from the engine. Be careful not to damage the cylinder head gasket and timing chain cover mating surfaces.
Note: An explanatory illustration may help to understand the procedures described below.
1 - bolts; 2 - washer; 3 - distributor drive gear; 4 - camshaft sprocket; 5 - tensioner assembly; 6 - tags; 7 - oil pump drive sprocket; 8 - chains; 9 - inner crankshaft sprocket; 10 - chain guide; 11 - nut; 12 - outer crankshaft sprocket; 13 - chain tensioner
13. Loosen the bolts securing the oil pump drive chain tensioner to the engine block. Lock the pump drive sprocket and loosen the mounting nut. Remove the chain, pump sprocket, and outer crankshaft sprocket assembly from the engine. Remove the tensioner.
Note: If the sprockets are too tight on the shafts, you will have to carefully pry them off with two levers to remove them.
14. Remove the timing chain tensioner bolts and the chain guide mounting bolts. Remove the guide with the tensioner - try not to lose the spring.
15. Lock the camshaft sprocket and loosen the mounting bolt. Remove the timing chain from the engine, as well as the camshaft sprockets, inner crankshaft and distributor drive.
Caution! After removing the chains, try not to turn the engine, as this can cause damage due to the valves hitting the pistons.
Checking the status
1. Wash all components in a suitable solvent and dry them with compressed air.
2. Check the chain links, sprockets, tensioner and guide pads for signs of excessive wear. Replace any defective components.
3. Make sure the plunger moves freely in the tensioner body in both directions. Replace if necessary.
4. Remove any traces of sealant from the timing chain cover and cylinder block. Check the cover for signs of deformation using a flatness gauge (steel ruler ribs) and a blade-type feeler gauge. Replace the cover if necessary.
5. Check the oil supply nozzle at the front of the engine for leaks. If necessary, clean the nozzle with a wire or blow it out with compressed air.
6. Using a punch, remove the crankshaft oil seal from the timing chain cover. Try not to damage the walls of the oil seal seat. Insert the new oil seal with the jaws facing the crankshaft.
Installation
Installation is carried out in reverse order.
1. Make sure that the engine is still in the TDC position of the end of the compression stroke of the first cylinder. This means, in particular, that the crankshaft and camshaft journals should be turned with the keyways upwards. If necessary, slightly adjust the position of the shafts.
2. Place the timing chain on the camshaft sprockets and the inner crankshaft sprocket. The shiny links of the chain should be opposite the timing marks on the sprockets (see accompanying illustration).
1 - tensioner assembly; 2 - distribution mark; 3 - shiny link; 4 - oil supply nozzle; 5 - chain guide; 6 - distribution mark; 7 - the shining link
3. Install the chain assembly with sprockets onto the engine, ensuring that the shiny chain links do not align with the timing marks.
4. Lock the camshaft sprocket and tighten the mounting bolt to 132÷142 Nm.
5. Install the chain tensioner assembly and tighten its mounting bolts to 7÷8 Nm.
6. Install the guide plate, adjust the tensioner clearance to 0 mm using the chain slack, and tighten the mounting bolts to 7÷8 Nm.
7. Place the oil pump drive chain on the pump sprockets and the outer crankshaft. Make sure that the pump sprocket is facing the long protruding part of the hub towards the timing belt cover.
8. Install the chain assembly with sprockets on the engine. Lock the pump sprocket and tighten the mounting bolt with a force of 24÷28 Nm.
9. Install the oil pump drive chain guide pad, then press it with your finger to take up the chain slack. Tighten the pad bolts with a force of 7÷8 Nm.
10. Apply a continuous cushion of high-quality sealant with a cross-section diameter of 2÷3 mm to the mating surface of the timing chain cover. Within five minutes of applying the sealant, press the cover to the cylinder block, trying not to disrupt the continuity of the cushion.
11. Tighten the cover mounting bolts in several stages with a force of 21÷26 Nm.
12. Lightly lubricate the inner surface of the crankshaft pulley around the perimeter with sealant, then push the pulley onto the shaft journal using a soft-faced hammer. Lubricate the threads and washers of the mounting bolts with sealant and screw in the latter, tightening them with a force of 142÷152 Nm.
13. Install the oil pan.
14. Install the distributor.
15. Fill the cooling system, start the engine and check for leaks.