Disassembly
Separate the gearbox from the engine, remove the coolant distribution pipe. Mount the engine on a stand. Remove the spark plug wires, distributor cap, rotor and spark plugs. Remove the oil filler plug with oil recirculation hoses. Remove the thermostat cover and thermostat, having first marked its position. Remove the cylinder head cover and rocker arm shaft. Remove the rocker arms and lay them out in order so that they can be installed in their original places during assembly. In the reverse order of tightening (Fig. 2.14), unscrew the cylinder head mounting bolts and remove the head together with the intake manifold and exhaust manifold.
Loosen the distributor mounting bolt and remove it together with the mounting plate. Remove the fuel pump with the heat-insulating gasket. Then the oil pump and the emergency oil pressure sensor. Remove the generator and drive belt. Remove the crankshaft pulley and oil pan. If necessary, lightly tap it with a mallet to separate it. Remove the timing chain cover; store its mounting bolts separately from other fasteners. Remove the oil deflector washer from the end of the crankshaft, marking its position (Fig. 2.15).
Turn the chain tensioner eccentric by hand and remove the tensioner shoe (Fig. 2.16). Loosen the mounting bolts and remove the camshaft sprocket with the chain.
Loosen the camshaft locking flange mounting bolts and carefully remove the camshaft (Fig. 2.17), turning it to recess all the tappets.
Then remove the tappets and lay them out in order. Using a universal puller, remove the sprocket from the crankshaft. Make sure there are marks on the main and connecting rod bearing caps (Fig. 2.18).
If necessary, apply marks before removing them Remove the connecting rod bearing caps with liners, remove the pistons with connecting rods. Install the caps on the corresponding connecting rods without tightening the bolts. Remove the clutch pressure plate and flywheel. Remove the crankshaft rear oil seal holder (Fig. 2.19).
Remove the main bearing caps. When removing thrust half rings 9 and 11 (Fig. 2.20), if they are to be used again, mark their position with paint.
Remove the crankshaft. Mark the bearings if they are to be reused.
Checking engine parts
Wash all parts and dry them with compressed air. Using a pressure syringe, pump trichloroethylene through the crankshaft oil passages. If necessary, separate the deposits with copper wire and blow out the passages. Clean the cylinder block oil passages in the same way and screw in or press in new plugs, having previously applied a sealant such as Loctite Frenetanch to them.
Check the technical condition of the washed parts, paying attention to the following:
- on the engine installed at the factory. the main journals may have a nominal size (without marks) or a size reduced by 0.25 mm (green chamfer dots on the crankshaft crank near the journal with a reduced size) (Fig. 2.21);
- on a factory-installed engine, the crank pins may be nominal (no marks) or reduced by 0.25 mm (green paint dots);
- on a factory-installed engine, the main and connecting rod bearing shells do not have any markings;
- on engines with a reconditioned crankshaft, the oversized main bearing shells have marks painted on the back of the shells;
- on engines repaired using the unit replacement method, liners of sizes increased by 0.50, 0.75, 1.0 mm have marks applied with paint on the edge of the liners.
In any case, it is necessary to measure the size of the connecting rod and main journals and the corresponding liners. The clearance between the liners and journals must be checked with a calibrated plastic wire.
Install the main bearing shells in the cylinder block bed and lay the crankshaft. Wipe the connecting rod (main) journal and the corresponding shell and cover. Place a piece of calibrated wire on the journal, install the cover and tighten to a torque of 8.8-10.2 kgf·m for main bearings or 2.6-3.3 kgf·m for connecting rod bearings. Do not turn the crankshaft. Remove the cover and, using the scale on the bag of wire, determine the gap size by flattening the wire. Measure the gaps for all main and connecting rod journals. Then, using a bore gauge, measure the ovality and taper of the cylinders. In case of excessive wear, bore the cylinders.
NOTE: The spare parts supplied are dry cylinder liners, installation of which must be entrusted to a specialist.
When installing piston rings in the cylinders one by one, measure the gap in the lock. Measure the gap between the ring and the piston groove. Replace the front and rear crankshaft oil seals. The rear oil seal is removed using tool 21.055 (Fig. 2.22), and to install it, you need a piece of pipe of the appropriate diameter or mandrel 21.059.
Assembly
Install the sprocket on the crankshaft, the mark on the sprocket should be facing forward. Using the pulley and its mounting bolt, seat the sprocket in place; do not hit the sprocket. Lubricate the valve lifters v install them in the appropriate sockets. Lubricate the bushings and journals of the camshaft with engine oil and carefully, so as not to damage the bushings, insert the camshaft from the front. Secure the locking flange and use an indicator to measure the axial clearance of the camshaft. If necessary, install a flange of the required thickness.
NOTE: When replacing the camshaft support bushings, ensure that they are installed correctly (Fig. 2.23).
Without lubricating, install the main bearing shells in the cylinder block bed and place the crankshaft on them. Install thrust half rings on both sides of the middle main bearing, with the antifriction side with the lubrication grooves facing the crankshaft (Fig. 2.24).
Lubricate the crankshaft main journals with engine oil and install the covers with liners, observing the installation marks: F - front support. C - middle, R - rear support (from the flywheel side). The arrows on the covers should point forward. Tighten the cover mounting bolts, then tighten them to a torque of 8.8-10.2 kgf·m. Bring the dial indicator leg to the end of the crankshaft (Fig. 2.25) and measure the axial clearance of the crankshaft; if necessary, replace the retaining rings.
Place the timing chain on the camshaft sprocket and install the sprocket on the camshaft, while simultaneously placing the chain on the crankshaft sprocket and paying attention to the position of the marks on both sprockets (Fig. 2 26).
Tighten the camshaft sprocket mounting bolts to a torque of 1.6-2.0 kgf·m and bend the edges of the lock washer onto the face of the bolt head. Turn the chain tensioner eccentric and install the shoe bracket on the axle. Release the eccentric and make sure that it rests against the teeth of the shoe bracket. Install the oil deflector washer on the end of the crankshaft with the convex side facing the timing chain. Install the chain cover with a new gasket in place. Lubricate with engine oil and install the crankshaft pulley. Install the crankshaft rear oil seal holder and flywheel. Lock the crankshaft with a screwdriver or a sharpened automatic transmission locking pin (Fig. 2.27) and tighten the pulley mounting bolts to a torque of 5.4-5.9 kgf·m.
Install the driven clutch disc with the protruding part of the hub towards the gearbox, center it using mandrel 21.052 and install the clutch pressure plate, tightening the mounting bolts crosswise in several steps to a torque of 0.7-1.0 kgf·m.
Lubricate the piston rings with engine oil and spread them, lubricate the cylinder bore and, using a clamp to compress the rings (Fig. 2.11), install the pistons with connecting rods into the corresponding cylinders, observing the installation direction: the arrow on the piston bottom points toward the valve timing drive (Fig. 2.28). The mark on the lower connecting rod head points toward the camshaft.
Turn the cylinder block over, lubricate the liners and install the connecting rod bearing caps according to the marks; tighten the bolts with a torque of 2.6-3.3 kgf·m. Install the oil intake pipe. Apply a layer of sealant such as Perfect Seal to the mating plane of the cylinder block with the oil pan. install neoprene gaskets on the front and rear crankshaft supports and side gaskets made of cork (Fig. 2.29), install the oil pan and tighten the mounting bolts in several steps: on a cold engine in the order indicated by the letters, then in the order indicated by the numbers (Fig. 2.30).
Perform final tightening on a hot engine with a torque of 0.8-1.1 kgf·m in the order indicated by the letters. Turn the crankshaft and set the piston of the first cylinder to TDC of the compression stroke. Install the ignition distributor, while the rotor should be directed perpendicular to the cylinder block. Install the cylinder head, the fuel pump with a heat-insulating gasket, connect the fuel hose to the carburetor nipple. Install the water pump, then its pulley and thermostat, paying attention to its position, install the thermostat cover with a gasket. Install the oil pump. Screw in the spark plugs using a 16 mm spark plug wrench and connect the high-voltage wires. Install the generator and adjust the drive belt tension.