Timing Chains
Removing and installing timing chains on V6 DFI engines
Preliminary work
1. Remove all engine compartment covers.
2. Remove engine.
3. Remove transmission.
3.1. For vehicles with automatic transmission, refer to Removing and Installing Transmission.
3.1.1. Remove flywheel.
3.2. For vehicles with automatic transmission, refer to Removing and Installing Transmission.
3.2.1. Remove drive plate for torque converter.
4. Remove intake-air distributor.
5. Remove cylinder head cover
6. Remove the timing-case cover at the top and bottom.
7. Set crankshaft to compression TDC for cylinder 1.
TDC for cylinder 1
Information
Component overview
Component overview for timing chains
1 - Timing chain housing
2 - Fastening screw
3 - Timing chain
4 - Outlet camshaft controller
5 - Sealing ring
6 - Oil pump
7 - Fastening screw
8 - Tensioning rail
9 - Chain tensioner for timing chain
10 - Sealing ring
11 - Pin
12 - Sprocket
13 - Sprocket
14 - Fastening screw
15 - Chain tensioner for drive chain
16 - Drive gearwheel for drive chain
17 - Drive chain
18 - Guide rail for drive chain
19 - Bolt
20 - Fastening screw on guide rail for timing chain
21 - Fastening screw on guide rail for timing chain
22 - Fastening screws for camshaft controllers
23 - Guide rail for timing chain
24 - Drive gearwheel for high-pressure pump
25 - Intake camshaft controller
26 - Valve for outlet camshaft controller
27 - Valve for intake camshaft controller
28 - Guide rail
Removing timing chains
Caution:
Damage to engine by turning crankshaft against the rotation direction of the engine (engine assembled)!
-> Never rotate crankshaft against the operating direction if the timing drive mechanism is mounted (timing chain jumps over).
-> Proceed carefully while working as otherwise the engine can be damaged.
-> Always turn the engine on the crankshaft and never on the camshaft as the timing chain may jump over.
-> After working on the camshaft wheels, the timing must be set.
-> Please observe general warning notes and working regulations.
Component overview for timing chains
1. Relieve the timing chain.
1.1. Unscrew the chain tensioner -9-.
1.2. Unscrew the bearing pin -11-.
1.3. Pull the tensioning rail -8- for the chain tensioner down and out.
1.4. Remove guide rail -23- by unscrewing the fastening screws -20 and 21-.
1.5. Remove timing chain from the camshaft controllers -4 and 25-.
2. Remove camshaft controllers.
Camshaft hexagon
Information:
Fix camshaft in place
^ To loosen the fastening screws on the camshaft controller, counter the relevant camshaft with an open ended wrench (a/f 27).
^ To prevent damage, remove the camshaft guide.
2.1. Remove outlet camshaft controller -4- by unscrewing the fastening screw -22-(). Counter the camshaft at the hexagon with an open-ended wrench when doing this.
Information:
Fix camshaft in place
^ To loosen the fastening screws on the camshaft controller, counter the relevant camshaft with an open ended wrench (a/f 27).
^ To prevent damage, remove the camshaft guide.
2.2. Remove intake camshaft controller -25- by unscrewing the fastening screw -22-(). Counter the camshaft at the hexagon with an open-ended wrench when doing this.
Information:
^ Always check all components, such as timing chains, sprockets, locking pins and chamfers for wear or damage. Always replace faulty components.
^ Always replace all fastening screws for the sprockets.
^ Before removing the timing chains, mark the running direction with a colored pen.
^ Maintain the same timing chain running direction during re-installation.
^ Never use a prick punch or file for marking.
3. Remove timing chain -3-.
3.1. Remove oil pump sprocket -13- by unscrewing the fastening screw -14-.
Block the crankshaft using special tool brace T10069.
Brace T10059
4. Relieve the drive chain -17-
4.1. Remove chain tensioner and tensioning rail -15- To do this, unscrew both fastening screws -2-.
5. Remove the drive chain -17-.
5.1. Remove the sprocket -12- from the oil pump shaft.
Installing timing chains
Component overview for timing chains
1. Install drive chain.
1.1. Check crankshaft position (compression TDC for cylinder 1).
Caution:
Timing chain running direction not maintained
^ Risk of damage to sprockets
-> Mark running direction of timing chains.
1.2. Place the drive chain -17- on the crankshaft drive gear wheel -16-
1.3. Position the oil pump shaft -1- with the flat side up so that it is horizontal to the marking -2-
Oil pump
1.4. The markings on the sprocket -12- and oil pump -2- must be perfectly aligned. If they are not perfectly aligned, it will not be possible to set the timing correctly.
1.5. Place the drive chain -17- over the sprocket -12- for the oil pump.
Then place the sprocket on the oil pump shaft while ensuring that the drive chain is correctly tensioned in the guide rail -18-.
1.6. Release the chain tensioner -15- using a small screwdriver, then press it together and install it.
The fastening screws -2- must always be replaced so that the chain tensioner is fixed in place with new fastening screws.
Then tighten the fastening screws with a torque wrench. -> Tightening torque: 8 Nm (6 ftlb.)
2. Install timing chain.
2.1. Check the position of the camshafts.
The camshaft guide T10068A must fit into the grooves on the intake and outlet camshafts.
Cylinder 1 must be set to compression TDC.
Camshaft guide
2.2. Fix the drive gearwheel for the high-pressure pump in place using adjusting tool T10363. Make sure that the marking -1- on the drive cam for the high-pressure pump is pointing straight up.
Securing drive gear wheel for DFI high-pressure pump
2.3. Guide the timing chain through the timing case from above.
Timing chain
2.4. Turn the sensor wheel -1- on the intake camshaft controller -25- as far as it will go to the right.
Position the intake camshaft controller on the camshaft and fix in place with the fastening screw. The fastening screw must always be replaced.
Then place the timing chain over the sprocket on the intake camshaft controller.
Make sure that the timing chain is tensioned correctly between the intake camshaft controller -25- and the drive gearwheel for the high-pressure pump -24-.
Sensor wheel on intake camshaft controller
2.4.1. Counter the camshaft at the hexagon with an open-ended wrench.
Tighten the fastening screw -22- using a torque wrench -> Tightening torque: 60 Nm (44 ftlb.) and then tighten further with -> Torque angle: 90°.
Camshaft hexagon
2.5. Place the timing chain over the sprocket on the outlet camshaft controller -4- Fix the outlet camshaft controller in place with the fastening screw -22-. The fastening screw must always be replaced.
2.5.1. Counter the camshaft at the hexagon -arrows- with an open-ended wrench (a/f 27).
Tighten the fastening screw -22- using a torque wrench -> Tightening torque: 60 Nm (44 ftlb.) and then tighten further with -Torque angle: 90°.
3. Tension the timing chain.
3.1. Install tensioning rail -8- for chain tensioner -9-
3.2. Fix the tensioning rail in place with the bearing pin -11- and then tighten using a torque wrench. Tightening torque: 10 Nm (7.5 ftlb.)
3.3. The sealing ring -10- on the chain tensioner -9- must always be replaced.
3.3.1. Then tighten the chain tensioner with a torque wrench. -> Tightening torque: 40 Nm (30 ftlb.).
3.4. Remove the camshaft guide T10068A.
3.5. Remove the adjusting tool T10363 from the drive gear wheel for the high-pressure pump.
4. After you have fitted the timing chain, turn the crankshaft twice and check the timing. Reset the timing if necessary.
Subsequent work
1. Fit the timing-case cover at the top and bottom.
2. Install the cylinder head cover.
3. Install intake-air distributor.
4. Install transmission.
4.1. For vehicles with manual transmission, refer to Removing and installing transmission
4.1.1. Install flywheel.
4.2. For vehicles with automatic transmission, refer to Removing and installing transmission.
4.2.1. Remove drive plate for torque converter.
5. Install engine.
6. Install all engine compartment covers.