15 replies to this topic

[yeti21586]

Vini has an 1100 engine i have no idea about gear ratios etc or what worm gear i have but i do know that i need a new one as my speedo is readying 30mph when im doing 40mph (my girlfriend was telling me i was going to fast so she drove in front of me at 30mph and my speedo was reading 20mph and in a 50mp limit she did 50 it was reading 40mph)

so was wondering how many teeth other people have on the worm gears they have in the engines with 13" wheels???

or anyway of knowing i just want to get it working properly

thanks in advance

YetI

Edited by yeti21586, 22 April 2009 - 09:53 PM.

[MRA]

Take a look at guess-works website, he has a funky speedo calculator

[yeti21586]

Take a look at guess-works website, he has a funky speedo calculator

i coudlnt work how to use it

[Guess-Works.com]

To find out the speedo worm/pinion configuration, you need the following information.

Final Drive ratio
Speedo TPM
Tyre size

Without those you can only 'guestimate' what the combination should be... if it's reading 10mph slow @ 50mph ( bearing in mind all modern car speedo's can vary from 0 to 10% fast, they cannot read slow ) then remove the speedo pinion and worm from your current box, count the teeth and then change the ratio so it spins the pinion 20% faster...

eg, if there's a 7/17 in there ( which I suspect there is ), then changing the 7 tooth worm to a 6 tooth worm 6/17 would give you the necessary increase.

[yeti21586]

cheers guesworks i shall try and take out the old one (not sure how to get to it lol and i cant find anyting in the haynes manual about taking it out)

[Guess-Works.com]

radiator out, n/s engine mount and bracket off, adaptor block off, and then two setscrews to remove retaining plate and pull it out.

[998dave]

they have in the engines with 13" wheels???

13" wheels, for a 1100, assuming the speedo cable is original this would result in a larger rolling radius, and could account for some of your issue.

Dave

[yeti21586]

they have in the engines with 13" wheels???

13" wheels, for a 1100, assuming the speedo cable is original this would result in a larger rolling radius, and could account for some of your issue.

Dave

cheers i had guesed that

[Disco Dan]

radiator out, n/s engine mount and bracket off, adaptor block off, and then two setscrews to remove retaining plate and pull it out.

Your website asks for the TPM of the speedo. I looked and only found the S/N and a three digit number. The speedo in my car says 800 a spare one I have says 750.

Would that be the TPM ?

Edit: both are KMPH speedo's.

Edited by Disco Dan, 24 April 2009 - 05:51 AM.

[Guess-Works.com]

radiator out, n/s engine mount and bracket off, adaptor block off, and then two setscrews to remove retaining plate and pull it out.

Your website asks for the TPM of the speedo. I looked and only found the S/N and a three digit number. The speedo in my car says 800 a spare one I have says 750.

Would that be the TPM ?

Edit: both are KMPH speedo's.

Yes, the number is TPK ( turns per Kilometre ), Quick and dirty way to convert to TPM is to multiply by 1.6

Edited by GuessWorks.co.uk, 24 April 2009 - 07:33 AM.

[yeti21586]

is this (the circled bit) were the speedo worm gear lives???

[M44K TS]

I think that's where the mechanical fuel pump sits

Edited by M44K TS, 03 May 2009 - 01:00 PM.

[yeti21586]

ok so were does the speedo cable
go

[monkey]

If you take the rad out, and just follow the speedo cable down with your hand... not the easiest of things to get to

[MRA]

If you follow the link, and in the left hand lower part of the picture there is a black cap..... underneath is the speedo drive boss that the cable attaches to....

http://mra-minis.co....products_id=189

click on the picture to enlarge it

Edited by mra-minis.co.uk, 03 May 2009 - 02:28 PM.