Dexta Tacho

[Nick]

I have done a search on this but cant find anything, but im sure ive seen it somewhere before.........can you take the tacho to pieces?

Reason I ask, whilst waiting for my engine block to come back, I have taken the dash panel apart for painting, the tachos hour meter works fine, but the needle has come off the spindle in the middle and just wants pushing back on, can you take the tacho apart? If so, has anyone got any photos of it?

Thanks

[Bensdexta]

Disassembly means removing/replacing the crimped-on retaining ring around the glass.

Not obvious how to do this without special tools.

Speedograph Richfield & I think, Speedy Cables + prob others can do it and service /calibrate your instrument.

But for a sum, typically around £100

[Nick]

I did wonder if that might be the case, I would like to keep the original tacho because of the hours etc so I will look into that.

Just another thing, its reading 44136, does that mean 44 thousand hours? Or 4 thousand, or more likely 14 or 24 thousand hours?

Thanks for your help ben

[Bensdexta]

My 1961 tractor's tacho has 5 digits, the last being 1/10th hrs.
Pic here:
http://www.fordsontractorpages.nl/phpbb ... f=3&t=3186

Be advised that there are at least two types of tacho, Smiths & AC, I think depending on the age of the tractor.

[Nick]

Hi ben,

I cant open that link, it keeps saying, 'link requested does not exist'.

Going by my serial numbers, mine is a late 58 / early 59 tractor, it only has five digits

[Bensdexta]

Link fixed, sorry 5 digits (not 6), ie xxxx.x hrs.
Suggest a search as there's other threads too.

[Nick]

Ah thats better. Ok my tacho is the same as yours, 1450rpm, digits at the top, but its got the pto and pulley speeds at lower rpms.

Interesting all these small differences in tractors, I will get it re-built when I get round to cosmetic issues, I got the engine block back now so engine re-assembly etc is next on the list

[Bensdexta]

Ah thats better. Ok my tacho is the same as yours, 1450rpm, digits at the top, but its got the pto and pulley speeds at lower rpms.

The gear ratios were changed slightly, I think to give more pto power.

[oehrick]

Nick,

Have you tried to see if the needle is magnetic ? (Sods law and experience makes me suspect it'll probably be Ali )

If it is steel, one of those small diameter magnets on an extension like the old radio aerials and two* children are needed.

Attract needle to underside of glass,

Manouver above spindle, rotate to orient to engine stopped position,

Rapidly remove magnet

Repeat innumerable times until it falls over spindle

When it does, rap back of tacho downwards onto breadboard

Might just get it going

* one will just get bored, two will fight for days to win the prize you offer