MG T-ABC

bit confusing title, sorry!
basically I have fitted a 5 speed box the speedo is now reading low, I think by about 10mph

I am going to have the instruments refurbished and hopefully get the speedo re calibrated but not sure [in fact haven't a clue] how to work out whatever it is I need to work out to get the speedo to read correctly

The rev counter also jumps slightly and never zeros on rest so I think that needs looking at too

Finally any thoughts on changing the low light bulbs for LED"s?

Hi tone,
I have had the same with my 1948 TC - I have fitted a Ford T9 5 speed gearbox and the speedo shows
15 % lower speed, the is normal after change ot this type of gearbox.
Your car as mine has a chronometric speedo an rev counter - these type of instruments you can`t calibtate.
What you need is a correction box to show the corrct speed.
The Richfield boys http://www.speedograph-richfield.com/index.html are able to assist you, the have done it
several hundred times.
Cheers Carl

You can calibrate them by changing internal gears. It's a difficult job but can be done by a professional who is experienced with chronometric instruments. The needle is supposed to be jumpy and doesn't always zero when you stop. It "updates" the speed once or twice per second. If you disconnect the cable at the gearbox and slowly turn it, the needle will jump down to zero.

Speedograph Richfield will recalibrate a chronometric speedo, I also have a type 9 gearbox and the speedometer is within a couple of miles per hour. The info they need is on their web site.

As Steve says the tacho and speedo only read every second or so.

The Jaeger Chronomeric's are a rare beast. Speedo Richfield says they will re-calibrate back to original specification, but only Smiths gauges. They then say " Other makes we will look at sympathetically and give an honest answer as to the feasibility of repair." They suggest contacting them for a chat.
here: http://www.speedograph-richfield.com/ht ... etric.html

Give Philip a call here http://www.chronometricspeedos.co.uk/page2.html

He sorted my gauges. They specialise in motor bike Jaegers but the internals are the same.