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MG Midget and Sprite Technical - Speedo Fix - What Could Go Wrong?

I realised at the weekend that the odometer in my MkIV Sprite's speedometer has stopped working. The trip one is still working properly.

According to the archive, the problem could be a dis-placed rotor, something broken or just stiffness due to being gummed.

I'll have a go at most things, but have never tackled a speedometer. What could go wrong?

What should I look for if I do take the plunge and open it up?

If it's just down to dirty innards, any recommendations for cleaning methods and products?

The archive provided link to JDO Instruments (http://www.jdo1.com/index.html) whose £130 charge seems pretty reasonable so perhaps the safest/most sensible option.

Any Thoughts?

Colin
C Mee

I had good service from JDO. I don't think lubricating cleaners are recommended for these speedos, although in my callow youth I used WD40 with success. I would go for JDO.
Les Rose

If the speedo is working and the odometer not but the trip meter is, that would suggest a mechanical problem as both the trip meter and the odometer are mechanically coupled to the input. The speedo needle is only magnetically coupled.
David Billington

My speedo (Mk2 Sprite) has just stopped working including the trip and odometer. It was my fault, tried to zero the trip whilst driving, should have done it stationary - I’m so brassed off!! Need to get it fixed, might try JDO or is there anywhere Lancashire based?
Les Robinson

Colin,
If you are unsuccessful I may be able to help - I have a spare
SN6142/06A. 1376 which I understand is for 3.9 diff.

I will need to sleeve the trip rod as the knurled knob bit has parted company- rather a silly crossed drilled pin in the 3mm shaft sheared it seems. A new dash rubber seal wood be good also as now rather solid. Mileage say 6k !!! Probably add another few !

Let me know if required - usual charity donation.
richard b

Richard,

That is a very kind offer but my Sprite has a 4.22 diff so I don't think I will be able to use yours but I will keep it in mind.

Many Thanks.
Colin
C Mee

This thread was discussed between 19/05/2026 and 20/05/2026

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