12 replies to this topic

[ad444t]

Hi all my mini has only bin road worthy for a week so tryin to learn how it goes but it seems like the final gear is a little off cause wen at 4 thou revs speedo readin 50-60 mph? Then telling a mate about it he said it could also be cam? If it is the final gear r they easy to change? Ne help appreciated

[Cooperman]

That is absolutely nothing to do with the camshaft.
It could be one of several things:
The FDR (Final Drive Ratio) is one of the optional competition ratios. For example, my Cooper 'S' has a 3.9:1 FDR and at 4000 rpm it is doing 58 mph in 4th gear.
It could be the speedo drive gear or the speedo itself.
You need to check the actual speed against the recorded speed and the accuracy of the tachometer.

[bmcecosse]

As above - compare the speedo with a GPS as first step.  

[ad444t]

If speedo readin correct is 4th easy to setup as at 4 thou I would expect to be doin 70+ with it bein a metro engine?!

[Ethel]

If the lump is straight out of a Metro that will account for some inaccuracy as they have bigger diameter tyres. 

 

http://www.guess-wor.../Tech/ratio.htm

[ad444t]

Hiya guys took it out again today with a GPS and at 55 on the clock it's doin 70! Seems to be out all the way thru the range

[Cooperman]

Just the speedo drive then. Either live with it or change the speedo drive gears.

[ad444t]

R they easy to change? Also I have an oil leak I've changed the drive shaft oil seals which cured it on the driver side but passenger side still leakin if u have ne ideas that would be great, I no ideally I need to get it on some ramps and av a look

[Ethel]

Possibly the bush in the end cover.

[ad444t]

Bush? End cover?!

[Guess-Works.com]

The diff side cover which you put the seal into, also has a bush, if this has worn then changing the seal is not going to stop it from leaking.

 

Easier to replace the diff cover than rebush it, unless you have access to a machine shop...

 

The speedo drives are not difficult, but to replace the worm drive you will need to remove the radiator and also the engine mount.

 

What you need to know before working out what you need is, the final drive ratio in the gearbox, wheel size and speedo turns per mile...

 

then you need this...

 

http://www.guess-wor.../Tech/ratio.htm

Edited by Guess-Works.com, 03 August 2013 - 07:52 PM.

[ad444t]

Well fortunately I av a second gearbox which came in with the car so will av a look on that!

[Cooperman]

Well fortunately I av  have a second gearbox which came in with the car so will av have a look on that!