SN4477/30 Speedometer

Post by **adam-wilden** » Sat Feb 02, 2008 12:57 pm

Hi,

The speedo in my 1959/60 948cc has started playing up - and it is cosmetially damaged so I intend to replace it (as well as checking the cable).

I had previously bought a good condition s/h gold face from (I was assured) another 948cc. It is an SN4477/30 (1376).

However, looking at it, the numbers go up to 90 (my existing clock only goes to 80) so I suspect it may be from an early 1098 and hence useless to me?

Can't find this SN number listed anywhere. Can anyone confirm what box this speedo needs to be accurate (assuming diff ratios are standard)?

Many thanks in anticipation for the access to the accumulated knowledge of the gestalt entity that is this forum...

And if indeed this is a gold-face for a 1098, and is therefore no use to me, has anyone got a working unit for a 948cc they would want to trade/sell?

Cheers - Adam.

Post by **bmcecosse** » Sat Feb 02, 2008 1:43 pm

The box ratios didn't vary - it was the diff that changed from 948 (4.55) to 1098 (4.22). What's the SN etc numbers on the old speedo ? The one you have will not be useless - it will still work.

Post by **mickessex** » Sat Feb 02, 2008 3:16 pm

If its any help my 1960 948 standard 4.55 diff, the speedo serial no. is

4407/00 1504
Checked with satnav and is within 2 miles per hour at 40mph.

If its just the chrome surround/glass thats damaged you could always just change the front of your existing speedo.

Mick

Post by **dave1949** » Sat Feb 02, 2008 3:52 pm

ive just dug out a speed i removed from a 1956 splitcreen.mileage shown 71637.
colour is in my opinion more silver than gold,has four warning lights top left ind,top right beam,bot left oil, bot right ign,80 mph no 51 114 401 09??

Post by **jonathon** » Sat Feb 02, 2008 5:40 pm

Remember sat nav is only accurate a to 7% margin.

Post by **Willie** » Sat Feb 02, 2008 7:24 pm

YES, the SN 4477/30 is for a 1098cc Minor between 1962 to 1964.If you give me your chassis number I should be able to give you the correct number but for your year it would probably be SN4466/00 or SN4477/00.

Post by **IslipMinor** » Sun Feb 03, 2008 12:25 pm

The significant numbers are the last 4, i.e. 1504, 1376 etc. These are the number of revs per mile that the speedo is calibrated for.

1504 is definitely for the 948, (I still have the original speedo for ours) and 1376 looks about right for the 1098. Also the 90 mph face was only 1098 as far as I know?

Post by **dave1949** » Sun Feb 03, 2008 1:04 pm

The significant numbers are the last 4

Have rechecked the numbers on the 56 splitty clock,def reads as previous above, last 4 nos 1000.

Post by **IslipMinor** » Sun Feb 03, 2008 1:44 pm

numbers on the 56 splitty clock

The skew gear ratio for the speedo drive is different on the 803 gearboxes to the 948 and later (remote gear lever type).

Oddly enough the 1000 revs per mile head gives a perfect odometer accuracy for our combination of 3.9 diff, Toyota 5-spd box and 185/70 x 13 tyres! The 'speed' part has been re-calibrated to match the different mph face.