Advice please - wrong speedo over reading

[Tony]

I am now getting to the end of my Series 2 Traveller rebuild having successfully got an MOT last week. I have installed a 1098 engine, 1098 gearbox, a 9/38 differential & 145 x 14 tyres. The affect of this is, not surprisingly, that the speedo is massively over reading. The speedo currently installed was the original from when it had an 803cc engine. I have 4 other speedos and I was wondering if I could swap the guts over into my existing speedo to get it to read correctly. Is there any way from the various numbers on a speedo, or from inspection of the mechanism, that I can determine the most suitable instrument? I could use trial and error but I’d rather not swap the speedo over too often!! Alternatively should I change the gearbox speedo drive gear? Any advice would be appreciated. Tony

[mike.perry]

You need a speedo with a TPM of 1408. These are available in gold for the early 1098 cars or black for the later 1098 cars. The TPM is the 4 fig no. after the serial no on the dial.

[Tony]

Hi Mike, Very many thanks. I have today put the guts of a 1408 TPM black speedo into my early brown speedo - a bit fiddly - but it works fine. If anything it might now be under-reading but I suspect that’s my imagination! Very many thanks for the advice. Tony

[mike.perry]

The early speedo has an 80mph dial, the 1408 has a 90mph dial so you are going to get the wrong readings, when the needle is vertical it will be reading 40mph on an 80mph dial and 45mph on a 90mph dial. You need a 1408 speedo off a 62-64 1098 Minor

[fussyoldfart]

I know well the task you had to swap the face on your speedo. I would find a measured mile or follow a modern with a known good speedo to check the accuracy of the odometer. While you're at it check the speedo at some speed that you are likely to drive a lot. (40MPH, 50 MPH?) If it is measuring the distance correctly leave it alone and learn to interpret the speedo reading. The originals were usually quite optimistic so yours may now be just right. Since you already know how to remove the speedo needle you could take things apart just once more and reposition it slightly to give you the right reading at one important point. Above and below that it will be "good enough for government work" and your car will have the desired appearance.

Darrell

[mowogg]

The 62-64 goldface speedo are 1376, not 1408. It is close enough though!

[mike.perry]

According to my records SN4410/00 is a bronze speedo with a 1408 TPM, SN4470/33 is a bronze speedo with a 1376 TPM.
Do you have a serial number for your 1376 bronze speedo?