Move one tooth on a gear wheel (asterisk) The camshaft gives approximately 18' crankshaft rotation. Moving the disc spring to the right in the direction of travel gives an earlier, to the left - a later start of intake. The adjustment is made as follows:
Loosen the camshaft sprocket bolt while holding the camshaft.
Mark with paint the relative position of the camshaft sprocket and chain and remove the sprocket.
Carry out the same test on the intake valve of the sixth cylinder.
6-cylinder engines, remove both rocker arms of the first cylinder using puller N 110 589 04 61 00 (for 8-cylinder engine N 123 589 03 61 00). To do this, turn the crankshaft in such a position that the top of the cam "watched" up. Replace both pressure devices with the measuring pressure device of the control device.
Install rocker arm without tension spring. Select the remaining valve clearance by turning the valve adjusting screw. The measuring pressure device must not detect a gap.
Mount and attach test device 110 89 10 21 00.
Inlet valve
With the intake valve closed, i.e. the cam points upwards, the dial indicator with the extension rod must be inserted into the control device on the inlet valve.
Then adjust the preload to 3 mm and fix the indicator.
Turn the rotating dial so that the large pointer is at zero.
Slowly turn the crankshaft in the direction of engine rotation until the dial indicator returns after 2 mm to a preload of 1 mm. In this position of the engine, read the readings on the vibration damper. It must match the value "Inlet valve open after TDC".
Exhaust valve
Carry out the same measurement on the exhaust camshaft. After setting the preload, rotate the crankshaft in the direction of engine rotation. The exhaust valve opens fully and the indicator points to 0. With the next closing of the exhaust valves, the measuring rod of the indicator returns to its position and the pointer starts to move. The small pointer should remain at 1 and the large pointer at 0. This corresponds to a valve travel of 2 mm when the outlet valve is closed.
Place a clean rag under the camshaft and remove the disc spring.
Insert the desired disc spring and install the camshaft sprocket. Repeat the check of the valve timing for another Las.
After installing an offset disc spring or a new chain, check the ignition setting.
Since both camshafts move in opposite directions, you need to pay attention to the installation order when installing the spring washer.
B-cylinder engines
Check the chain for damage, wear or excessive elongation. In case of repair, there is an open circuit with a connecting link. When repairing the engine, it is imperative to install a closed (endless) chain.
Remove spark plugs.
Remove cylinder head cover.
Remove the chain tensioner or remove the compression spring with the tensioner installed (6-cylinder engines).
Remove the right camshaft rocker to avoid reverse rotation of the camshaft. if
Close the case with a cloth.
Open the circuit with the separation device.
For installation:
Attach the new open link chain to the old chain.
Turn the engine slowly at the crankshaft in the direction of rotation. At the same time, pull up the old chain until the open link reaches the top position of the camshaft sprocket. The chain must remain engaged with both camshaft sprockets during rotation.
Unhook the old chain and connect the ends of the new chain.
Install both fixing washers. Turn the engine over and check the adjustment marks.
If necessary, check the valve timing.
Install the chain tensioner or install the compression spring in the chain tensioner. If the chain tensioner was removed on a 6-cylinder engine, then it must be disassembled, then assembled on an assembly machine and then installed.
Install the rockers in the correct order.
Adjust the valve clearance on the right camshaft.
Install the cylinder head cover. Screw in the spark plugs.