Smiths Speedo - SN 3273/04

[SENC]

Thanks Mike, very helpful article!

John, thank you.

1 - Yes, the drag cup appears to rotate fairly freely and spring back, though if just turned slightly (say in the 10-20mpg range), it is 50/50 getting hung there.
2 - Yes, the magnet wheel does rotate when the drive is rotated.

After reviewing the flannery website and Mike's article, I'm guessing primary potential causes are some dust/lint/grime buildup or maybe lack of lubrication inhibiting free movement. That might jibe with the speedo getting "stuck" - and perhaps in disconnecting the cable, removing the gauge from the car, and partially disassembling it I dislodged enough to get the movement I'm seeing now. I will test for better pointer movement with a drill (in reverse), but regardless of the findings think I'll at least go as far as disassembling the drag cup and magnet wheel to inspect, clean, and lightly lubricate.

As always, would welcome guidance, words of caution, or even contradictory opinion from those who have experience.

[john.p.clegg]

Be careful when removing the needle , I have bent spindles before,,, even snapped one that was V tight .

Work over a white sheet , makes losing bits harder.....I think it just needs some thin lubrication , WD40 ? Silicon fluid?

John

[nmauduit]

I will test for better pointer movement with a drill (in reverse), but regardless of the findings think I'll at least go as far as disassembling the drag cup and magnet wheel to inspect, clean, and lightly lubricate.

be careful with the lubricant you use (WD40 is not a lubricant), you don't want it to become sticky over time and have dust collecting at the contact tip (possibly jewel).

[661]

I've just had some contact with the firm below

http://www.chronometrics.co.uk/

May be useful, although my degree of contact wasn't enough to allow a judgement on the quality of their work

[ericbushby]

Hi Graeme,
Have you noticed that `Chronometrics` state on their website that they do not repair magnetic instruments. Yours is magnetic. They may not be the best people for the job. Speedy cables did a good job for me.
It seems to me that it needs stripping and cleaning.
I do not know what lubrication the disc pivot needs. If it is hardened steel then a light thixotropic oil like clock oil would do nicely. That is, if it should be lubricated at all.
Eric in Burnley
1967 S3SE DHC

[DWP Industries]

Hi. you need to read this:

https://vsip.info/repairing-jaeger-amp- ... -free.html

It will help you service your Speedo. If you have any problems with your rebuild, just PM me.

The best way to remove/replace the pointer, is to hold the aluminium disc still, and rotate the pointer whilst pulling it off the spindle. Should come off easily this way. Same to adjust the position of the pointer after refitting it. Do not lever off the pointer with a fork/screwdriver, etc., unless it is really tight. Clean the mechanism (but NOT the number drums, the numbers will come off) with alcohol and lubricate sparingly with clock oil. You can use a thin grease on the main shaft with the magnet and the Cross-Gear that is driven by the brass worm. Do not lubricate the brass worm itself. Use oil/grease sparingly. When reassembled, push in the main shaft at the cable end with a suitable screwdriver and make sure that the aluminium disc does not bind and still moves freely. Message me if it does not!

[SENC]

The needle is a press fit that didn't want to give up after 55 years, but got a small drop of penetrant into the gap where it fits onto the spindle and it eventually popped off with levers. Getting the odometer spring back on was quite fiddly. But other than those 2 things it was a simple job. Note, I did not fully disassemble the odometer, as it appears to be working OK - so just blew it off, lightly. My biggest recommendation for any who tackle a similar job is a clean, white space (small bits) and a backstop when refitting the spring. It went flying on me once and I was quite lucky to find it.

Adding some pictures for those who want to see the innards...

[SENC]