Trying to get a fully working Speedometer

[mrsnak]

I've got one speedometer where the odometer works, but the speedo is lifeless.

Just got a wonderful gift of another speedo from a UK friend (who drill-tested it before bringing it all the way to California).
Speedo works great, but the odometer doesn't.

I made a mess of the hairspring trying to fiddle with another speedometer I had, so I don't to revisit that area, but how easy might it be to perform a transplant of the good odometer to the speedo with the bad one?

Would I be better off determining what part had failed in the bad one?

Nice to have a working speedo, at any rate.

[bmcecosse]

You should be able to mix and match parts - just be v careful with that spring!

[fussyoldfart]

I've got one speedometer where the odometer works, but the speedo is lifeless.

Just got a wonderful gift of another speedo from a UK friend (who drill-tested it before bringing it all the way to California).
Speedo works great, but the odometer doesn't.

I made a mess of the hairspring trying to fiddle with another speedometer I had, so I don't to revisit that area, but how easy might it be to perform a transplant of the good odometer to the speedo with the bad one?

Would I be better off determining what part had failed in the bad one?

Nice to have a working speedo, at any rate.

I happen to have a speedo on my bench that I swapped out for the same reason, ie speedo works but odometer will not advance. I took it apart this evening to see what I could learn.[frame][/frame] I set all the wheels to 99999.2 and ran it with a drill to watch it turn over to 00000 but it would not turn the whole set.[frame][/frame] A little more fiddling got it to zeros.[frame][/frame] but the tenths wheel would still not move the next one and I cannot see how the whole wheel set can be removed without taking the hair spring off its spindle. I'm not brave enough to try that so I'm stuck. Not a problem for me as I have already replaced the unit but maybe someone else knows how to get the wheels to work properly.

Darrell

[MarkyB]

Presumably the left hand numbers will be stiffer as they move so much less, I'd try dribbling some lubricant, not oil though, round them.

Does the whole group twitch when trying to go past 000000?

[mike.perry]

If you are swapping parts between speedos then both speedos will need to have the same TPM or the readings will not be accurate.

[fussyoldfart]

Presumably the left hand numbers will be stiffer as they move so much less, I'd try dribbling some lubricant, not oil though, round them.

Does the whole group twitch when trying to go past 000000?

No, the 10ths wheel is moved by a little plastic ratchet device that just slips if things are too tight to move. The third picture shows it clearly. I suppose if one lets it run it will just wear out the white hook or strip one tooth off the black wheel.

This is a classic setup for "Once you break something you will see how it was put together"

Darrell

[MarkyB]

The trouble is the next line reads, you'll wish you'd studied it harder before you went and broke it .

[MartinLowe]

from the look of the last picture there are several teeth stripped on the last cog

[mrsnak]

Well, I'm going to take the new one back out and scrutinize it more carefully. I did learn my lesson to stay away from the spring!
I'd like to be hopeful & think that the odometer just needs a little lube, but it's usually worn or broken teeth on any old speedo.

[simmitc]

I don't want to dash any hopes, but although I've rebuilt numerous Minors and am generally good on electrical and mechanical items, all I've ever managed to do with a speedomoeter is to b*gg*r it up completely. There are specialist companies that can fix them without any problem, so I guess that it's a question of having the right knowledge and right tools. Maybe somebody on here will be able to fill in the gaps, but don't hold your breath.

[LouiseM]

The mileometer (odometer) on my speedo stopped working on the way to last year's National rally. I was told that this is because the plastic cog was worn and that it is possible to replace these if you can find a less worn one in another speedo. I'm not sure how easy this is though as I took the easier option and picked up a second hand speedo for £10 and just replaced it

[mrsnak]

The mileometer (odometer) on my speedo stopped working on the way to last year's National rally. I was told that this is because the plastic cog was worn and that it is possible to replace these if you can find a less worn one in another speedo. I'm not sure how easy this is though as I took the easier option and picked up a second hand speedo for £10 and just replaced it

All well and good for you UK folks who have used Morris speedos seemingly behind every tree
Here in the Morris desert of Snakland, we often have rely on the kindness of strangers (or pay top dollar from the usual US suspects) to help us with our cherished British imports.
Replacing that one gear (if that is the problem) might be an option, but having been inside a Smiths speedo before, it's not for the timid.
We have a holiday here tomorrow (Thanksgiving, where malcontents from the UK came and ruined America for the native Americans. ;-)), so I will be delving into the speedo. Will report back after significant work has been done, proper beer has been downed and turkey has been consumed.

[mrsnak]

Spent some time with the old one apart, and the mechanism just looks too delicate for an amateur like me to try swapping parts with.
I may try to find a shop that specializes in speedo resto to see if they might want to take on the challenge.
In any event, I did some testing as to the speedo's accuracy, given that I have a Datsun motor in the car, with the GPS app on my iPhone.
Basically, at 40mph the speedo reads 30, so I now just do the calculations.

[mike.perry]

Try a speedo with a different TPM. There is a table of speedos on the Series MM website, http://seriesmm.mmoc.org.uk Car Ident.

[rayofleamington]

there is a firm that recalibrates and repairs speedos - maybe you could send both and ask them to make a good one out of both?
The upside is that you'll get an accurate non-wobbly speedo, unlike a normal second hand one!

Yousshould find them on google if you look for speedos and cables ;-)

[bmcecosse]

The rebuilt speedos are very expensive - just buy a speedo from ebay once you have worked out what tpm you need. The Classic mini ones fit straight in - and are usually ~£5 to buy.

[ian.mcdougall]

Don't know of one for a fiver bmce but you could try this one



http://cgi.ebay.co.uk/SPEEDOMETER-BLACK ... 45def76325

[bmcecosse]

Ha! Well - that's for the silly cars with gauges in front of the driver - and crazy price anyway.
This is more like it - but ask them what tpm
http://cgi.ebay.co.uk/MINI-CLASSIC-CENT ... 2a0c4739d1
And this one I know is a bit more - but does include 2 extra gauges.
http://cgi.ebay.co.uk/OLD-MINI-SPEEDO-H ... 5d2c5aad71

[simmitc]

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Re: Trying to get a fully working Speedometer

New postby bmcecosse » Tue Nov 30 2010 8:36 pm
The rebuilt speedos are very expensive - just buy a speedo from ebay once you have worked out what tpm you need. The Classic mini ones fit straight in - and are usually ~£5 to buy.

Be wary, a standard Mini speedo will NOT fit straight in a minor. The dial and body may look the same, but the lugs are different and will not fit through the hole without considerable modification.

[bmcecosse]

It's hardly a 'considerable' modification - the rim etc fits the hole in the dash perfectly - and it's a few seconds work to modify the lugs slightly!