What thread?

[AussieJohn]

Does anyone have a clue as to the thread on the speedometer where the cable screws on. It seems to be 12mm at 1mm pitch but I didn't expect a metric thread; any thoughts?

[AussieJohn]

Come on guys, where are you techy types with all the answers? cheers, John.

[garyeanderson]

A google search turned up this post

http://www.triumphrat.net/classic-vinta ... reads.html

"The cable thread for Smiths tacho/speedo is metric: 12mm x1.0 .
It seems to be common on Japanese gauges too.
The square drive on the inner cable for Smiths gauges is not metric,its 1/8" square.
Japanese inner cables have a metric square,usually 3mm.

Thread size shouldn't be a problem.The size of the square drive could be a problem."
--------------------------------------------------------------------------------
I tried a 1/2 x 20 as I don't have any 12mm anything that I know and the nut starts on the speedo cable thread on the speedometer but only turns a turn or two before it starts to lock up so the 12 x 1.0mm would seem to be a good start. All I really know it the speedo cable threads onto the speedometer and thats what counts.

Gary

[elansprint71]

Come on guys, where are you techy types with all the answers? cheers, John.

Might be worth asking the folks at Speedy Cables?

[AussieJohn]

Thanks guys, cheers, John.

[ceejay]

Hey guys...chiming in here a bit late.

Threaded boss on the back of the speedo is: 12mmDia X 1mm thread pitch.

Ceejay

[garyeanderson]

Hey guys...chiming in here a bit late.

Threaded boss on the back of the speedo is: 12mmDia X 1mm thread pitch.

Ceejay

Thank you CeeJay for confirming the internet search. Sometimes it does actually gives you the right answer if you spend a few minutes looking and putting in various search terms.

Gary

[ceejay]

When I read the posting I just wandered out to the W/shop as the elan
dash is sitting on the bench waiting for some work to be done,
so it was easy to grab the vernier and thread form gauge to check.
And then saunter back to the PC to post the results.
So no probs.
Ceejay.

[AussieJohn]

Thanks everyone for all the advice; it is for a friend who is wanting to use an original speedometer with a mt75 gearbox that has an electrical speedo output. A company in the States is making a motor drive to mount on the back of the speedo to retain the mechanical odometer. cheers, John.

[Elanman99]

Thanks everyone for all the advice; it is for a friend who is wanting to use an original speedometer with a mt75 gearbox that has an electrical speedo output. A company in the States is making a motor drive to mount on the back of the speedo to retain the mechanical odometer. cheers, John.

Thats sounds an interesting approach. Unless I have missed something obvious the whole thing could get quite complicated and be quite costly. I would have thought that the mounting thread details are the least of the problems. Its the sort of thing I might have considered doing for myself but it certainly would not be economically sensible.

The motor driving the speedo will either have to be a stepper type (might not be silent) or servo controlled to exactly mimic what would have come out of the original gearbox pinion shaft.

I have the impression that I have seen visually identical, but electronically operated, instruments advertised recently, they would be a much more sensible option.

Ian

[ardee_selby]

Does anyone have a clue as to the thread on the speedometer...

When you said "thread" I thought you meant thread as in a "forum thread". I've been searching the archive for bl**dy ages without success! D'OH!

Note to self: Read all posts carefully!

Richard

[c42]

A bit late here but I believe that it is very easy to convert the MT75 box from electric speedo drive to mechanical.

Regards
John

[prezoom]

Abbott Enterprise also makes a converter from digital to mechanical. Can find them at: www. atrol.com.

Rob Walker
26-4889

[AussieJohn]

Wow, a lot of good info. here, I will pass it on, cheers.