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Right. Last go I had the center of 1 of the stock gears wire EDM'd to fit a hub I made.

This go I will use the stock gears as-is by making a new stubby lower shaft that finger couples to an adapter I make for the trans input shaft. The coupler setup will seal with any small misalignment drop gear case to trans case and lets the gear lower gear remain stock (actually his is the OEM clutch gear but unmodified now). The replacement gears arrived yesterday and look good so now I need to finish the shaft and adapter designs and make them and some bearing adapters for whatever bearing I pick out for the new shaft. This will be much better I think, the old setup scarred me a bit but this I'm pretty confident in.

Great news.

I started roughing it out..the blue is the current hub cut down and the orange the new shaft, the gear will sit in the middle with a bearing on each side

The unmodified gear will sit in the middle of the orange part?

Also, Houseman Autosport (I think they're in Canada) has done a couple of things for the Fiero community. I know they're into one-offs... just not cheap.

yes, like this. An OEM ring nut on the right to hold it on, then bearing on the end. The other bearing goes on first and is retained by the gear but I've not started looking at bearings yet so things will still change a bit.

These are parts I can make. I will need to send them out for heat treat and I can't cut the metric thread for the ring nut, but a friend of a friend says I can come visit his lathe that can so I just need to finish up the design and get on with it.

Once again, major engineering for the win. I will be watching.

I have purchased a number of ring nuts over the years and have found several that had the threads cut small. Some took lapping compound to get them to spin on. One I chased the threads on the lathe with a thread cutting insert. So, if you buy aftermarket ring nuts, measure them before. I am sure your threads will be spot on, if the nut doesn't fit, check it first.

_________________
Wade Williams
Master Ferrari Tech
Restoration Tech
Engine Machinist
Fabricator
Racecar Driver

Very cool. What kind of fit do you size the orange piece for?

It will be different in different places. Even the 2 bearings will likely be different as 1 is retained by the gear and nut so maybe up to 1 thou clearance is fine but the other will want a light press. The gear wants low radial run out but a slip fit... so say 1-2 thou on 2 of the smallest dia and maybe 5 everywhere else. then 5-10 on the orange/blue mate so it goes together easily but is unlikely to rattle, then orange to blue along the axis 10-120 thou should be fine...I'll aim for 60-80 maybe?

As I said, I never loved what was done on the Goldsmith style conversions for a number of reasons. There are 4 of them driving around so it clearly works, but it does bend a few design rules and my choice to add an outer bearing fixed one concern (high stress at the gear/shaft interface) but made alignment related issues worse as there were now 4 bearings on what is effectively 1 shaft. This new design fixes all that I think as the new shaft is fully supported in the outer casing and delivers only torque to the trans shaft which is back to factory design bearing wise and I've removed the side loading the shaft originally had. I'm thinking tapered rolled bearing to locate the shaft in the case but that means I will need to plan to shim one of the bearings to get the end play right....so not a perfect design but I think it addresses all the concerns I had with the other design and shimming the bearing is a 1 and done kind of thing and I can set that up in the bell housing before final assembly so I can live with that.

Cleaning continues

and I even sorted out 15 years of drawings, notes and receipts


But I did take a break for some very important work....I changed the look of the gemellocattivo badge. My car has the silver with black inlay badges not the black with white so I cleaned out the white and remove the black off the face and will stick it on once the clear it dry

Which direction does the axial thrust from the gear helix angle go?