Checking Drive Belt
WARNING: This page is about a different variant/trim than selected.
WARNING:
Rotating components
- Danger of limbs being trapped or severed
- → Disconnect power supply to the drive motor of components or to the battery.
NOTIFICATION
Drive belt removed incorrectly
- Risk of damage to drive belt
- → Only remove the drive belt when it is cold.
- → Replace damaged drive belt.
NOTIFICATION
Drive belt breaks and becomes jammed
- Risk of damage to components (trim panels, electric cables, etc.)
- Leaks at the crankshaft vibration damper sealing ring
- Vibration damper can overheat and lose its strength
- → Following belt breakage, check adjacent components and the interior of the engine compartment for damage. Repair or replace damaged parts.
- → Find out why the belt broke. Check deflection rollers or crankshaft vibration dampers for prior damage.
- → If the drive belt is jammed, replace the vibration damper.
Information
- If spark plugs must be changed in the course of maintenance operations, the drive belt should be checked when the spark plugs are removed. The engine can then be cranked easier.
Information
- The following table shows the type of damage that necessitates replacement.
Damage symptoms for drive belts
| Item | Type of damage | Explanation |
|---|---|---|
| -A- | Slight crack in a rib | Drive belt is OK |
| -B- | Hairline crack that runs across the entire belt width, or the butt seam is damaged. | Replace drive belt |
| -C- | Crack running down to half of rib height | Drive belt must be replaced if there is more than one crack running down to half of rib height. |
| -D- | Crack running to base of rib. | Replace drive belt |
| -E- | Crack running to traction cord or edges so worn that the traction cord becomes visible. | Replace drive belt |
| -F- | Rib detachment | Replace drive belt |
| -G- | Rib fracture | Replace drive belt |
- Using chalk, mark the drive belt in the area around the tensioning roller. > Marking drive belt
Marking drive belt
- Turn the engine at the crankshaft for as long as required in direction of rotation of the engine until the chalk mark is back at the same place. During this time, check the drive belt at the deflection roller for signs of damage.
Replace damaged drive belt.
- When turning the engine, visually check deflection rollers for smooth operation, intact running track and play.
Replace noisy and damaged rollers.
- Refer to 137719 Removing and installing deflection roller