FAN BELT Tension Adjustment
Correct tensioning of the fan belt is important to ensure efficient operation of the cooling and charging systems. Excessive strain will cause rapid wear of the belt, and place undue strain on the water pump and dynamo or alternator bearings.
When correctly tensioned, a total deflection of 1/2 inch (13 mm) should possible under normal finger-tip pressure at the midway point on the longest belt run between the two pulleys.
If adjustment is required, slacken the dynamo (alternator mounting bolts) and the adjusting link nut, and move the dynamo/alternator towards or away from the engine as necessary to achieve the correct tension. Avoid over-tightening the belt. Apply any leverage necessary to the drive end bracket only, and not to any other part of the alternator, the lever used should preferably be of wood or soft metal. Recheck the belt tension after tightening the adjusting link nut and the mounting bolts.
Belt Replacement The condition of the belt should be checked periodically. If nicked, cut, excessively worn, or otherwise damaged, the belt should be replaced. If the belt is noisy in operation, check for misaligned pulleys.
To replace the belt, proceed as for adjusting, but press the dynamo/alternator fully towards the engine, and detach the belt from the pulleys. Maneuver the belt between the fan blades and the right-hand top of the radiator cowling. On models with the sixteen bladed fan, feed the belt between the individual blade tips and the cut-outs in the cowling flange .
Fit the new belt in the same manner, ensuring that it is not twisted, and adjust the tension, as described above. Do NOT attempt to lever a new belt onto the pulleys as this can easily cause damage to the belt or pulleys.
The tension of a new belt should be checked after approximately 100 miles (160 km) use.