Replacing the timing chain on a 612 series engine
Illustrative material on replacing the timing chain of the 612 series engine is presented in the illustration, to which all references in the text refer.
Removal
1. Remove the cylinder head cover.
2. Remove the vacuum pump.
3. Remove the cooling fan assembly.
4. Using a special tool, separate the chain links and remove it from the engine.
Installation
1. Place the new chain (2) in its regular place and use a special tool to connect the links.
2. Having completed the necessary preparations (see Section Removal and installation of timing drive components), install the chain tensioner (14).
3. Check that the camshafts are in the correct basic position (see Section Checking the basic position of the balance shaft (628 series engines only)).
4. Install the vacuum pump.
5. Install the cooling fan clutch.
6. Install the cylinder head cover.
7. Start the engine and check for signs of developing leaks.
M628
Examination
Replacing the timing chain on a 628 series engine
1 - Intake camshaft; 2 - Drive belt pulley; 3 - Label; 4 - Blocker
1. Illustrative material for checking the condition of the timing chain of the 628 series engine is presented in the illustration, to which all references in the text refer.
2. The degree of chain stretching is assessed by checking the position of the pulley (2) of the drive belt on the locked intake camshaft.
3. Remove the right cylinder head cover.
4. Remove the accessory drive belt.
5. Turn the engine in the normal direction (arrow), and lock the intake shaft (1) using the tool (4).
6. If the pulley (2) offset is more than 11° (after TDC), the chain must be replaced.
7. After completing the inspection/replacement, reinstall the accessory drive belt and cylinder head covers.
Removal and installation
Replacing the timing chain on a 628 series engine
1 - Old timing chain; 2 - New timing chain; 010 - Holder
Illustrative material on replacing the timing chain of the 628 series engine is presented in the illustration, to which all references in the text refer.
Removal
1. Open the hood and fix it in a vertical position.
2. Remove the cylinder head covers.
3. Remove the cover of the first bearing of the right cylinder head exhaust camshaft (see Section Removal and installation of timing components).
4. Attach the holders (010 and 011) to the right head.
5. Disassemble the links and remove the old chain (1) from the engine.
Installation
1. Place the new chain (2) in its regular place and connect its links.
2. Check that the basic position of the camshafts is correct (see Section Setting the base position of the camshafts).
3. Check that the balance shaft is in the correct basic position (see Section Checking the basic position of the balance shaft (628 series engines only)).
4. Remove the holders (010 and 011).
5. Install the right cylinder head exhaust camshaft first bearing cap.
6. Install the cylinder head covers.
7. Close the hood.