Having had a better look at your photo dave, I notice that the sprocket is on the outside of the chassis rail, not the inside. It looks as if you have to remove the sprocket, and the chain, before you can take off the flanged plates (10 & 12) and slide the end of the shaft (with the bearing still on it) through the chassis rail. You will have to take the screw (4) out from the end of the shaft so you can remove the retaining washer (5) then the sprocket (6). You take the two flanged plates off the right side bearing as well as the left (sprocket side) bearing.(Numbers refer to the Greenfield parts diagram).
