I finished off the adapter plate for fitting the Type 9 gearbox into the Scimitar SE5A today – and managed to get a decent workout into the bargain when it came to finishing the profiled edges! The finished plate bolts to the new gearbox with the four counterbored holes which are large enough to accept a thin 19mm socket and will leave the bolt heads below the surface of the plate. The original Scimitar bellhousing will then bolt on to the other six holes and the slightly bigger hole in the top of the plate (which is actually on the right of the photo) gives clearance for the selector rail. The adapter plate is made as thin as possible in order to use the shorter of the available first motion shafts and to bring the position of the gearbox as near to original as possible. Because of this I decided to maximise strength by using a really good quality bit of steel. The workshop machinery all coped well with the task although the swarf was coming off the big Willson lathe in rather an interesting shade of blue. The plate was profiled to external shape with a bandsaw and then finished with a file before polishing with emery, and it was the latter two operations which also made me turn a rather interesting shade in the summer heat!
The next job will be to spot face the original bellhousing so that the bolts (some of which now face rearwards instead of forwards) will have a good surface on which to tighten. One extra job had been unforseen until the new gearbox arrived: The single rail selector has to pass through a newly bored hole in the bellhousing and it will need a cover making for it in order to seal oil. I shall be producing a spot facing for this also when the bellhousing is set up on the milling machine.