having problem finding spares for the Speedometer drive mechanism. Problem arose when the bearing on the differential shaft began to break up (Don't know why it did) however parts of the bearing casing jammed in the speedo gears thus causing the speedo not to work. When stripped down the nylon teeth on both gears where flattened and to date cant find replacements anywhere can anyone advise. Vehicle is 2001 Fiat Ducato 1.9 td.