morris minor speedo

[estepona1999]

Can anyone tell what,apart from the colour of the face,is the difference between the silver and gold faced speedo's ? Which would be correct for my 1958 traveller ?
Also I am upgrading the engine from 948 to 1098 does this determine a particular speedo is needed.The dif was upgraded by the previous owner,so will the affect it? Thankyou again I am still a novice on this car.

[MorrisMinor-65-1000]

Also I am upgrading the engine from 948 to 1098 does this determine a particular speedo is needed.The dif was upgraded by the previous owner,so will the affect it? Thankyou again I am still a novice on this car.

Provided the gearbox hasn't been changed, the speedo won't be affected by the engine change. 1098 gearboxes have a fractionally taller 2nd gear ratio, but I imagine you wouldn't be able to tell the difference and it's only one gear.
That said, if the diff has been changed for a different ratio, the speedo WILL be affected in ALL gears. If it is a taller diff (ie first number is lower than standard diff - eg 3.9 down from 4.22) the speedo will under-read and you'll be travelling faster than indicated. If it's a shorter diff (ie first number is larger than what was standard) it will over-read and you'll be travelling slower than indicated.

I believe 4.55 was the standard differential ratio for all non-commercial 948 models, which was pushed up to 4.22 for 1098 models, but could be wrong on that.

[bmcecosse]

As above -your car was on a 4.55 final drive (the 'diff' is the same...) and hopefully it was been changed to a 4.22 or (even better!) a 3.9. The correct speedo for a 4.22 will have 1408 tpm on the dial - beside the odometer.

[mike.perry]

The relevant figure is the 4 fig tpm, turns per mile, displayed on the speedo face after the serial number. This determines which speedo is suitable for which diff. ratio
See the chart on http://seriesmm.mmoc.org.uk Car Ident, Speedometer Identification

[estepona1999]

Thankyou all for the information,I seem to think the diff was upgraded to a 3.9,I am pretty sure about that.In that case which speedo do I require please? The gearbox is due to be changed to the ribbed case instead of the smoothcase gearbox that was fitted.

[bmcecosse]

A 1408 speedo will be very nearly accurate on a 3.9 final drive - with 155 X 14 tyres.

[estepona1999]

Thanks for that I will start looking for one,though I am not sure where to look !! The 1408 will be on the face of the speedo I take it?

[Declan_Burns]

You can see it here.
Regards
Declan[frame][/frame][frame][/frame]

[estepona1999]

Thanks to everyone for all your help and thankyou Declan for the photos,now I know where to look,cheers Roger

[mike.perry]

A 1408 speedo with a gold face and 90mph dial will be found on 1098 Minors between 1962-64 and black face between 65-71.
The same speedos will be found on 1098 LCVs between 62-64 and 65-71 but have a tpm of 1504 to suit the LCV 4.55 diff