137819 Removing and installing drive belt

WM 137819 Removing and installing drive belt

Preliminary work

1. Remove intake manifold (air box) in front of throttle housing. -> 243519 Removing and installing air box for throttle housing (Y-shaped pipe ahead of throttle valve) 243519 Removing and installing air box for throttle housing (Y-shaped pipe ahead of throttle valve)

Removing and installing drive belt

NOTICE

Drive belt removed incorrectly

- Risk of damage to drive belt

-> Only remove the drive belt when it is cold.
-> Replace damaged drive belt.

NOTICE

Drive belt breaks and becomes jammed

- Risk of damage to components (trim panels, electric cables, etc.)
- Sealing ring on crankshaft vibration balancer can start to leak
- Vibration balancer can overheat and lose its strength

-> Following belt breakage, check adjacent components and the interior of the engine compartment for damage, and repair or replace damaged parts if necessary.
-> Find out why the belt broke. Check deflection rollers or crankshaft vibration balancer for prior damage.
-> If the drive belt is jammed, replace vibration balancer.

WARNING

Rotating components

- Danger of limbs being trapped or severed

-> Disconnect power supply to the drive motor of components or to the battery.





Belt drive





1. Mark the rolling direction of the drive belt with chalk.
2. Open connecting clip on coolant hose. Lift coolant hose aside.
3. Relieve and remove the drive belt. To do this, turn the belt tensioner clockwise at the hexagon => Belt tensioner hexagon using a ring wrench (a/f 30) or change-over ratchet with socket => Loosening the belt (relieve the drive belt) and remove the drive belt from the tensioning roller. Then slowly relieve the belt tensioner.





Belt tensioner hexagon





Loosening the belt

4. Remove the drive belt.
5. Fit the drive belt as shown. At the end, only leave a loose loop of the drive belt on the belt tensioner ready for fitting.
5.1. Fit used drive belt in the rolling direction according to removal marking. Fit the drive belt straight on all pulleys without tilting it (leave loop in front of tensioning roller). Finally, turn the belt tensioner clockwise at the hexagon using a ring wrench (a/f 30) or change-over ratchet with socket and place the drive belt around the tensioning roller. Then slowly relieve the belt tensioner.
5.2. Relieve the belt tensioner by turning it clockwise again at the hexagon and fit drive belt loop. Tighten the belt tensioner.
6. Check that the drive belt is positioned correctly on the pulleys. => Belt drive





Belt drive





7. Turn engine clockwise at the vibration balancer and check that the drive belt is fitted correctly. This work is much easier during a service because the spark plugs are removed.
8. Move coolant hose into the correct position and close the connecting clip on the coolant hose.

Subsequent work

1. Fit intake manifold (air box) in front of throttle housing. -> 243519 Removing and installing air box for throttle housing (Y-shaped pipe ahead of throttle valve) 243519 Removing and installing air box for throttle housing (Y-shaped pipe ahead of throttle valve)