Speedo Drive Gear & Calibration

[carockwell]

The tranny in my 1380 pre veto uses a 3.1 final drive. The speedometer reads about 18% slow. This tells me that the speedo drive gear in the tranny is set up for the standard 2.79 final drive that appeared in a lot of later minis. Is there a different gear sold for the speedo drive in the tranny when using a 3.1 differential? It is not very practical to change anything in the speedometer unit. I know the 3.44 had its own drive gear and that there was a different gear for the 2.79, not sure about the 3.1.

[MiniDave]

I think you mean the 2.76....and yes it has a different speedo drive and pinion both.

You can go on John Guess' website - guessworks.co.uk - and see the different numbers.

[tmsmini]

John can take care of you. I have purchased the matched sets for the 3.1 drives in our cars. You need to know which speedometer as they have different turns per mile.

http://www.guess-works.com/Tech/speedo.htm

http://www.guess-works.com/Tech/ratio.htm

[MiniDave]

BTW, I lived in Sandy Eggo for about 20 years, what part of town are you in? I lived in Bay Ho.....

[tmsmini]

If you figure out what you need, list the numbers as I have assorted pieces from converting to electronic speedos.
There are also two different size diameter gears, so the two must match.

[MiniDave]

if you have a spare 7 pinion and a 16 drive I  could use them....