Lotus Elan

Speedo drive

PostPost by: mcclelland » Sun Feb 21, 2016 10:27 pm

Hello all,
this may have well been covered before, so I apologise to all those who love to point this out and complain when it would be easier to contribute something positive.

I have a standard S4 Elan, gear box, wheels and tyres etc. I am about to change the diff from the 3.77 unit to the 3.5 unit. Can anyone pls. tell me which speedo drive I will need to swap in the gear box, that is 22, 23 or 24 teeth. I believe they are colour coded too. Many thanks for your help.

Regards, George.
George McC.
1968 S4 Elan dhc.(now sold)
1973 Plus2 S130/5
1994 Elan M100 S2
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PostPost by: elanner » Mon Feb 22, 2016 12:35 am

My collected notes say:

- 23 teeth, Black for 3.55 diff
- 24 teeth, Green for 3.77 diff
- 25 teeth, Blue for 3.9 diff

And there was a rumor that Dave Bean had/has some 22 teeth gears that are apparently OK for a 3.55 with bigger tires. I've no idea if this is true.

Anyway, the gear wheels don't seem to be available any more. At least, I've never been able to find one. But before worrying about changing it why not check the speedo against a GPS speedo? You might find that it's quite accurate. I think the original set up tends to be optimistic about the speed, and fitting a lower ratio diff eliminates the optimism. At least, that's what I found.

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