Timing Cover: Service and Repair
WM 153319 Removing and installing timing-case cover
Technical values
Preliminary work
1. Remove the engine. -> 100119 Removing and installing engine 100119 Removing and installing engine
2. Remove transmission from engine and suspend engine on the assembly support -> 1001IN Securing engine on assembly support (mounting bracket) [1][2]Specifications 1001IN Supporting the engine on the body
3. Drain engine oil. For details, see -> 170117 Draining and filling engine oil (changing engine oil) Removal and Replacement.
4. Remove drive belt. For details, see -> 137819 Removing and installing drive belt Service and Repair.
5. Remove coolant hoses in front of the timing-case cover. Don't forget the holder. => Coolant return line on turbo engine, for example
Coolant return line on turbo engine, for example
6. Remove both valve covers. -> 158219 Removing and installing cylinder head cover Service and Repair
7. Remove vibration damper. -> 137619 Removing and installing pulley (vibration balancer) Service and Repair
8. Remove joint flange behind the vibration damper and do not re-installed old flange. -> 137419 Removing and installing crankshaft sealing ring for pulley/vibration balancer Service and Repair
9. Remove oil pan and oil guide housing. -> 175019 Removing and installing oil pan 175019 Removing and installing oil pan
Information
Component overview
Timing-case cover seals
Applying sealant (filling openings in metal seal)
Applying sealant before fitting valve covers
Tightening sequence for timing-case cover
Chain tensioner, joint flange
Removing timing-case cover
NOTICE
Timing-case cover removed incorrectly
- Risk of damage to seal between oil pan and crankcase
- Risk of engine leaks
-> Always reseal the oil pan when removing the timing-case cover.
1. On turbo engines, remove positive crankcase ventilation completely in front of the timing-case cover => One-way couplings for ventilation on turbo engines. Be careful with connections that cannot be loosened.
One-way couplings for ventilation on turbo engines
2. Remove belt tensioner and deflection rollers on the timing-case cover. To do this, lever off the cover and loosen the screws. => Belt drive
Belt drive
3. Unclip vacuum lines from the cable duct if fitted -arrows-.
Unclipping vacuum lines at the cable duct
4. Unscrew fastening screw -1- at the cable duct -2-.
Releasing cable duct
5. Remove chain tensioner. -> 153619 Removing and installing chain tensioner Service and Repair
6. Remove the timing-case cover. To do this, loosen all screws in reverse order. => Tightening sequence for timing-case cover
Tightening sequence for timing-case cover
7. Carefully remove timing-case cover. Lever off gently if necessary (bonded with sealant).
Modification to timing-case cover seal from mid-2010
Information
- A modified metal seal has been used for the timing-case cover since mid-2010.
- The modified metal seal has an open cut-out on the side for applying sealant instead of the closed top opening.
- Existing metal seals can be used up.
- The sealant must be applied along the new contour as shown in the illustration.
- The small, closed top openings are filled with sealant in the familiar way.
Sealant application - new
Sealant application to right cylinder bank near the chain tensioner -1 and 2-
Sealant application to left cylinder bank -7 and 8-
Installing timing-case cover
Information
If cold or excessively low-tempered components are sealed to each other by applying sealant, leaks can occur because of condensed water forming or components distorting. Components must be uniformly at least => Temperature: 17°C.
Information
- Acetone can be used to clean the sealing faces. Ventilate this for 5 minutes before applying more sealant.
1. Clean dirt and grease off the sealing faces of the engine and timing-case cover.
Information
Carefully apply Loctite 5900 sealant on the timing chain housing in such a way that sealant cannot get into the screw holes when you fit the timing-case cover. Loctite 5900 can increase the friction coefficient of the aluminium screw. The sealant must not overflow.
2. Fit the new metal seals on the timing-case cover. Fill the openings in the metal seals with sealant. Apply sealant at the specified markings on the engine => Applying sealant (filling openings in metal seal with sealant) => Timing-case cover seals. Apply the sealant in such a way that no excess sealant can expand into the engine when the timing-case cover is fitted (blocked oil ducts).
Applying sealant (filling openings in metal seal with sealant)
Timing-case cover seals
Applying sealant (filling openings in metal seal)
3. When fitting the timing-case cover, press the tensioning rail away from the sprocket (cylinder 1) towards the timing chain using a screwdriver (second worker required).
4. Fit timing-case cover straight on without letting it slip out of place.
5. Screw down all fastening screws by hand. At this stage, the screw heads should not be all the way down.
Information
- The timing-case cover must be aligned using a dial gauge or steel gauge.
- The timing-case cover must not project over the lower part of the crankcase. Even the slightest projection must be corrected.
- It must not be < ( -dimension A- )1/10 mm ( -dimension A < 1/10 mm- ).
6. Press the timing-case cover upwards slightly and tighten the fastening screws (approx. 1 - 2 Nm (0.5 - 1.5 ftlb.) so that the timing-case cover is slightly jammed. Then align the timing-case cover.
7. Align the timing-case cover within 5 minutes and screw it on.
Aligning timing-case cover with a dial gauge
Information
The timing-case cover must not project over the crankcase. The maximum offset is => Length: 0.1 mm.
1. Insert the dial gauge into the universal dial gauge bracket and position it so that the dial gauge has a preload of about 1 mm. => Adjusting the preload
Adjusting the preload
2. Set dial gauge scale to 0. To do this, place the dial gauge bracket on a completely flat surface (e.g. crankcase flange) and turn the dial gauge scale until the pointer is at 0. => Resetting dial gauge scale
Resetting dial gauge scale
3. Measure offset. To do this, push with the bracket starting from the lower part of the crankcase towards the timing-case cover (the base of the dial gauge bracket is not located on the same component as the dial gauge probe) and measure the offset => Measuring the setback distance. The timing-case cover must not be set back by more than 0.1 mm. Even the slightest projection must be corrected.
Measuring the setback distance
4. Align the timing-case covers by tapping lightly with a rubber hammer. => Aligning timing-case cover
Aligning timing-case cover
5. Once you have aligned the timing-case cover, tighten two fastening screws on the left and right of the timing-case cover base hand-tight. Then check the position of the timing-case cover again using the dial gauge. => Checking position
Checking position
Securing timing-case cover
Information
- The tightening specifications for the basic engine are stored centrally. -> 1001IN Tightening torques, tightening sequences, assembly overviews [1][2]Specifications. Tightening torques and assembly instructions for other assemblies (e.g. chassis, electrics, transmission or body) or for peripheral engine equipment can be found in the corresponding documents.
1. Tighten the fastening screws to the relevant parameters in the sequence shown. => Tightening sequence for timing-case cover
Tightening sequence for timing-case cover
Carry out further assembly work =>
2. Secure cable duct at the front right.
2.1. Route cable duct on the timing-case cover and fit the screw.
Securing cable duct
3. Clip in vacuum lines at the cable duct -arrows-.
Clipping in vacuum lines at the cable duct
4. Fit belt tensioner and deflection rollers on the timing-case cover. Also fit screws and cover. => Belt drive
Belt drive
5. On turbo engines, fit positive crankcase ventilation completely in front of the timing-case cover => One-way couplings for ventilation on turbo engines.
One-way couplings for ventilation on turbo engines
Subsequent work
1. Install oil guide housing and oil pan. -> 175019 Removing and installing oil pan 175019 Removing and installing oil pan
2. Fit new joint flange behind the vibration damper. -> 137419 Removing and installing crankshaft sealing ring for pulley/vibration balancer Service and Repair
3. Set the timing. To do this, connect the vibration damper. -> 150516 Setting timing for camshafts Procedures
4. Fit vibration damper. -> 137619 Removing and installing pulley (vibration balancer) Service and Repair
5. Install both valve covers. -> 158219 Removing and installing cylinder head cover Service and Repair
6. Fit drive belt. For details, see -> 137819 Removing and installing drive belt Service and Repair
7. Fit coolant hoses in front of the timing-case cover. Don't forget the holder. => Coolant return line on turbo engine, for example
Coolant return line on turbo engine, for example
8. Fill in engine oil. For details, see -> 170117 Draining and filling engine oil (changing engine oil) Removal and Replacement
9. Refit transmission.
10. Install the engine. -> 100119 Removing and installing engine 100119 Removing and installing engine