FH - rebuilding the ATD

 The only job that's getting in the way of timing the engine is the rebuild of the automatic timing device or ATD. I've got a kit with excellent instructions from Priory Magnetos, and this will replace the fibre gear and the springs on the old original timing unit.

The first part of the job is to remove this collar which holds the whole unit together:

After various activities with old cars in the past I've got a number of different pullers and ball joint splitters and all sorts of things like that knocking about. This bearing puller make sure work of grabbing hold of the collar and pulling it off:

The colour allows you to release part of the ATD from the section that carries the fibre wheel. The next job is to use a 3/16 drill to remove the rivet heads that hold the ATD to the fibre wheel. The pillar drill makes sure work of this little job:

You can then knock the rivets out, and essentially the whole thing will fall apart. You might have to untangle the springs and the bob weights but that's as far as it goes. This the units now completely disassembled and it's had a little while in the cleaning tank to get rid of all the old oil.

The next job is to replace the fibre wheel with the new rivets that are supplied in the kit. Before I do that I have a good look at all the parts to make sure there is no damage. In fact the unit has been a part before because one of the stops that prevents the unit over advancing has actually been replaced by some thinner piece of material braised in place. It seems to be in about the right place and it functions so we'll leave it as is. The second problem is the back plate is a little bit bent for some reason but that strains out quite easily with a small hammer and some judiciously placed taps.

With all that straightened out, we can rebuild the ATD using some new rivets and a new fibre wheel from priory magnetos. This goes together quite easily and it's riveted up using the ball pein of my hammer.

With the rivets in, we can assemble the loose parts of the ATD using some new springs and some lubrication for the moving parts. Then we can put the unit in the vise and squeeze up to refit the collar.

That's it, done for now until we're ready to time the engine.