What size are the threads on the terminal studs? Are they a common size or odd?
I thought so but my die(cheep)was fighting to go on so I stopped before I did any damage. I will get one of those Dermal wire wheels to clean the gunk out tomorrow.
The 10-32 thread is very common, but as far as I know all the nuts being made in that size today are 3/8" across the flats. The nuts Ford used were 7/16" across, often with the hole slightly off center. I made my own 7/16" nuts, but used brass. I prefer the look of them, and they won't rust.
The coil box should have nuts securing the porcelain to the stud, but the coil box wires are secured by knurled nuts, not hex nuts.
Royce, is that true for all years? I see that Lang's carries the knurled nuts, but their description says they are for 1909-1913 cars.
They show a brass hex nut for 1914 and up cars.
I don't know about all years, but at least through 1917 Ford used knurled nuts on the coil box and timer terminals.
This is the original cast iron Ford script timer from my '17 torpedo runabout:
Thanks, Royce. Now I know why they provide them in packs of 15, 10 for the coil box, 4 for the timer, and maybe one spare in case you drop and lose one?
I'm not sure about '14 up, but the wood coil boxes use a cross knurl, not a straight knurl. As Royce mentioned the later T's use a thin hex nut. I get the later style nuts off old junk coil boxes, and save the good parts for later use.
I make the correct 7/16" hex nuts and all of the different correct thumb nuts for all coilboxes, 1909-27.
Sorry; forgot the photo. L to R: hex nut, 7/16 x 10-32; Heinze thumb nut; Kingston/JB thumb nut, and Ford thumb nut.
Do you definitively know what years the "Ford thumb nut" and "7/16 ATF X 10-32 hex nuts" were used on coilbox terminal bolts?
Ron the Coilman
They were used at least 1913-16. I can't definitely say but I'm pretty sure the hex nuts were changed to copper plated steel about the time the brass tops on the coils were dropped and continued for a short time after that before changing to 3/8" copper plated nuts of the same thread, which by the way never changed on the terminal nuts; they were 10-32 from 1909 right on through. I doubt that it took Ford very long to start using the same nut on the terminals and the coil bridges.