Belting it out

A rattling noise that occurs at higher rpms near the top of each gear and may at first seem to be a dying mainshaft bearing or oil throwing wheel gone bad may in fact have a much simpler fix. Opening the bonnet whilst attempting to duplicate the behaviour reveals that the screeching sound seems to be coming from farther forward in the engine bay and may well be nothing more than a slightly loose fan belt. According to the manual (p.57) the belt tension is checked on the right side between the fan and crankshaft pulleys, and should depress 8-11mm under thumb pressure.

On the left side there is bolt on the adjusting bracket for the dynamo and a pivot bolt under it. Loosening both of these just enough and using leverage makes accurate movement easier to calculate than if they were completely loosened. In this case a long pair of blacksmiths tongs was used to lever the dynamo slightly outward and very accurately take up a little slack, taking care not to over tighten the belt and put undue pressure on the bearings. When the appropriate setting is reached the nuts are re-tightened to lock it in. If the issue persists the belt can be readjusted slightly tighter until the issue is dealt with.