SV started making a weird sound and so after inspection found one pinion/prop shaft had developed excessive lash. The fix was to make a double layer masking tape shim and attach to the bottom of motor so that when mounted in the frame it put a bias on the gear end towards the prop gear and tightened up the mesh. The pinion gear had started to wear in the middle so had to slide it approx. 1mm further down the motor shaft
While in there I lubed the prop shaft and bearing with grease using a FREE dosage syringe from my local grocery pharmacy.