The 'E' Type Forum

Hi guys, I would like to change in the future my diff ratio from 3.54 to 3.07 and change the units from miles to kilometers thus I will need to calibrate my speedo.

The question is: who cares? sorry...

No, the question is... What are the options?

1.) I can send my speedo together with all necessary data to someone and they will do it for me. (they will change just gears in the speedo)

2.) Can I change the speedo drive gears in the gearbox? The angle drive gearbox for speedo will stay the same.

You could either have the speedo re-calibrated or find the correct one s/h. Serial numbers of speedometers here: http://etypeuk.com/forum/viewtopic.php?t=951

If you want your existing speedo serviced and re-calibrated:

Speedograph Richfield (instrument restoration/calibration): http://www.speedograph-richfield.com/
Speedy Cables (instrument repair, restoration, calibration): http://www.speedycables.com/index.html
Speedometer calibration: http://www.westnet.com/~mfrank/Speedometer/Smiths.html
John D Ostick (instrument repairs, re-calibration): http://www.jdo1.com/

Thanks David! I didn't mentioned the third option of correct speedometer because I hit Submit button instead of Preview

Now I have next question... How accurate is that database?

There is: SN 6322/03A; xxxx; 3.31; mph; 6.40x15 SP41

This is the number on my speedo with 1312 TPM. But I have 3.54 diff wich is according to Jaguar certificate original.

So I will have to look for speedo with Kmh face but with wich serial number or TPM...

Hi,

I know this doesn't help with the speedo calibration, but you can change a speedo to km/h just by changing the face - available from SNG. The odometer still reads in miles of course. I don't know whether the calibration people will re-paint the face of the speedo, so if you want a km/h face, this may be an option.

Regards,

Thanks Simon, I know about that. I will probably find correct speedometer and restore it.

I sent mine to Speedograph in Nottingham. If you look on their website they ask for a whole lot of information about your car to correctly calibrate it; cost me about 70 pounds plus postage. The guy I spoke to on the phone was a bit grumpy to deal with.

As I haven't yet finished putting my car back together again I can't comment on accuracy but it is certainly very clean.

Hello all,

I have currently car dismantled and thus cannot verify the turns as described in Richfield's form. Should you please provide me with your numbers of cable turns per 6 drive wheel turns (as they recommend "push car for 6 wheel turns and count cable turns") I have calculated mine for 3.54 differential and 1.25 gearbox angle drive and I got number around 10 1/8. What were your results, preferably for 3.54 differential but other differentials are welcome as well.

Many thanks to all for your help,

Pavel
Dec1966 LHD OTS 4.2

Pavel

Have you checked out the list in this post?: http://etypeuk.com/forum/viewtopic.php?t=951

Nazdar Pavel,

I have a Series 1 4.2 FHC with 3.54 diff. The TPM on the original speedo is 1312.

Martin