3.152 Series » How to check the drive belt(s)

Renew a belt if it is worn or damaged. If twin belts are fitted, they must be renewed together.

To check the detection, press down the belt with the thumb at the centre of the longest free length and check the deflection (A). With moderate thumb pressure 45 N (10 Ibf) 4.5 kgf the correct deflection of the belt is 10 mm (3/8 in). If twin belts are fitted, check/adjust the tension on the tighter belt.

How to adjust the belt tension

1. Loosen the pivot fasteners of the alternator (B1) and the adjustment link fasteners (B2).
2. Change the position of the alternator to give the correct tension. Tighten the pivot fasteners of the alternator and the adjustment link fasteners.
3. Check the belt tension again to ensure that it is still correct.

If a new belt is fitted, the belt tension must be checked again after the first 25 hours of operation.