I don't like the "thick oil" lubrication method used in this design. The bush bearing relies on the viscosity of the oil to stop it seeping away and running dry. The thrust pad in the base has no way of retaining oil either. I decided to do something about this and started by grinding out some channels on the back wall as per picture "A". I then bent some 0.5mm aluminium to form a Dam across the open side of the casting and stuck it in place with "Chemical Metal" as in picture "B". This filler is strong and resistant to oil.