Timing Chain Tensioner: Service and Repair
WM 153619 Removing and installing chain tensioner
Preliminary work
1. Remove right air guide on the turbo engine. For details, see -> 242719 Removing and installing air cleaner air box 242719 Removing and installing air box for air cleaner
Air cleaner outlet on turbo engine, right
Removing chain tensioner
Make sure the vehicle cannot start. To do this, switch off ignition and remove ignition key.
1. Make room for removing the chain tensioner by loosening the wire harness.
1.1. Open the retaining clip -3- ( -arrow B- ) and remove the B+ line -4- ( -arrow C- ).
Wire harness on generator
2. Disconnect plug connection for generator.
2.1. Release plug connection for generator -1- ( -arrow A- ) and disconnect it -arrow B-.
2.2. Pull off plug connection for generator -1- together with the line bracket from the B+ line -arrow C-.
Disconnecting plug connection for generator
The chain tensioner can be easily reached from the right wheel housing using the ratchet extension.
NOTICE
Incorrect handling of crankshafts
- Risk of damage to the timing system
-> Never turn the crankshaft against the rolling direction or when the chain tensioner is removed.
-> Proceed carefully with your work.
-> Only turn the engine at the crankshaft.
-> Reset the timing after working on the camshaft.
-> Observe general warning notes and working regulations.
Information
- The chain tensioner can be removed in any timing chain position.
- The timing chain cannot by dislodged by removing the chain tensioner (screw securing timing chain in place).
- The crankshaft and camshafts must not be turned when the chain tensioner is removed.
3. Carefully press down the B+ line upstream of the chain tensioner. Carefully unscrew chain tensioner. -5- The chain tensioner is made of aluminium. Check the thread for signs of damage. Clean the thread if there is slight abrasion. Replace sealing ring.
Installation position of chain tensioner in timing-case cover
Installing chain tensioner
NOTICE
Incorrect handling of crankshafts
- Risk of damage to the timing system
-> Never turn the crankshaft against the rolling direction or when the chain tensioner is removed.
-> Proceed carefully with your work.
-> Only turn the engine at the crankshaft.
-> Reset the timing after working on the camshaft.
-> Observe general warning notes and working regulations.
Information
- The chain tensioner can be removed in any timing chain position.
- The timing chain cannot by dislodged by removing the chain tensioner (screw securing timing chain in place).
- The crankshaft and camshafts must not be turned when the chain tensioner is removed.
Information
- If the chain tensioner is removed, the aluminium sealing ring must be replaced.
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. The chain tensioner is made of aluminium. Check the thread for signs of damage. Clean the thread if there is slight abrasion.
2. Carefully screw chain tensioner in as far as possible with your hand. -5- Tighten chain tensioner. The chain tensioner can be easily reached from the right wheel housing using the ratchet extension.
Installation position of chain tensioner in timing-case cover
3. Check crankshaft by turning it two turns in a clockwise direction. Make sure that it turns easily.
4. Connect plug connection for generator.
4.1. Clip in plug connection for generator -1- together with the line bracket on the B+ line -arrow A-.
4.2. Connect plug connection for the generator -1- ( -arrow B- ) until the generator plug connection -1- engages securely.
Connecting plug connection for generator
5. Fit wire harness in front of the chain tensioner.
5.1. Insert B+ line -4- into the retaining clip -3- ( -arrow B- ) and close the retaining clip -3- ( -arrow C- ).
Installing heat shield for generator lines
Subsequent work
1. Fit right air guide on the turbo engine. For details, see -> 242719 Removing and installing air cleaner air box 242719 Removing and installing air box for air cleaner
Air cleaner outlet on turbo engine, right
