Which speedo

[jimmy167]

I have fitted a gold faced speedo 4407/00 to my 1960 saloon ,it reads slow by about 8mph .
What speedo should I have ,I believe the car has original diff /gearbox and engine .
Thanks Jimmy

[oliver90owner]

Don’t know, but somewhere on the speedo it should show how many revs per mile.

[geoberni]

SN4407/00 was only used on Series 3 Traveller with 4.55 Diff. So probably the wrong one for your Saloon.

See the Potteries branch website: http://potteries.mmoc.org.uk/ID/Speedo.htm

It's not a complete list, but it's very useful nonetheless.

[ManyMinors]

Why would the speedo be different for a Traveller? Saloon and Traveller are identical mechanically aren't they for a given year? The differential is certainly the same ratio on each. I do agree that there are many different speedos and various different differential ratios over the years. It isn't uncommon for a speedo to be a little inaccurate - especially after 60 years

[oliver90owner]

Why would the speedo be different for a Traveller? Saloon and Traveller are identical mechanically aren't they for a given year? The differential is certainly the same ratio on each. I do agree that there are many different speedos and various different differential ratios over the years. It isn't uncommon for a speedo to be a little inaccurate - especially after 60 years

That said, the law states that speedos can indicate up to 10% too high, but must not indicate less than the true speed.

[don58van]

I can't say whether your speedo has the correct turns per mile for your car. But I would point out that these speedos can gradually drift toward under-reading over the years. The reason is that they depend on a spinning magnet creating drag on a disk connected to the the needle. Over the years, magnets tend to weaken -- thus reducing the deflection of the needle. The magnet can be remagnetised by an advanced hobbyist or commercial speedo specialists.

Don

[geoberni]

Why would the speedo be different for a Traveller? Saloon and Traveller are identical mechanically aren't they for a given year? The differential is certainly the same ratio on each.

I agree it's odd, and looking at the AKD3541, the Potteries branch list may be a bit suspect in that regard.

Here's the various Mile versions of Speedos, with their relevant fitment references. You'll note the 4407/00 and 4466/00 are bracketed together:

Speedo Capture.JPG (131.14 KiB) Viewed 1411 times

[jimmy167]

Thanks for all the useful comments , I have ordered a speedo from ESM and will let you know if I have made a good choice once it is fitted .
I am hoping my present speedo is just old and as suggested its magnets are weak .
I don't mind a small override and my Traveller indicates about 3MPH high .My 1960 Saloon is more like 8 to 10 MPH slow which is not good .

[jimmy167]

Speedo arrived this morning , fitted works smoothly ,reads slightly high . I went for the SN4406/00 .
Great service from ESM .

[svenedin]

I also have a reconditioned speedo from ESM and it seems pretty accurate. The only way I can judge the accuracy is to compare it to those digital speed awareness signs and it seems spot on at 20 and 30 mph. I don't have a GPS to compare the speedo to.