Speedo

[sixdogsisback]

My speedo seems to have finally given up. The cable is rotating but the speedo does not move, either the MPH or the milometer. It was reading very fast anyway. Can anyone tell me where I can get it overhauled and re calibrated. My diff is 4.55/1. I was told by someone that there is a company who specialises in this sort of thing. I have bought secondhand speedo s from auto jumbles in the past, but none have worked, so give these a miss.

thanks, Clive

[C6Dave]

J D O Instruments. Highly recommended and fast service compared to others out there: http://www.jdo1.com/index.html

[mogbob]

Another source of repair/resto/recalibration is http://www.speedycables.com .A satisfied customer, no other connection.
Bob

[bmcecosse]

It will cost a small fortune - what's wrong with the second hand speedos ? Test them with a reverse running electric drill gun - with a small square bit. Are you sure the problem isn't cable related? It may not be entering the speedo far enough to engage. But test the speedo(s) first. For a 4.55 final drive you need a 1508 tpm speedo.........

[sixdogsisback]

It will cost a small fortune - what's wrong with the second hand speedos ? Test them with a reverse running electric drill gun - with a small square bit. Are you sure the problem isn't cable related? It may not be entering the speedo far enough to engage. But test the speedo(s) first. For a 4.55 final drive you need a 1508 tpm speedo.........

I've bought secondhand speedo s from auto jumbles and none of them work. If someone has a good secondhand speedo I'd buy it.

I will test my old speedo with a drill. As you say, it could still be the cable fooling me. but the old speedo is not the correct one for my car. It's black and the correct one is gold. It reads about 50 mph when I'm doing 30 mph. At 50 mph it's right round to go again. Even allowing for axle ratios, I don't think it should ever read this fast. I have a correct speedo for the axle ratio, but it does not work and it is this one which I would send for repair.

Clive

[sixdogsisback]

I think now, that it's worth fitting a new cable anyway for what they cost. I've just ground a square on an old drill bit and tested the original gold speedo, which seemed to be faulty, and it seems to work with the drill driving it. If the square holes are a bit worn and the square on the old cable worn, they might add up to not driving the speedo and my being fooled into thinking the speedo is duff. You never know with old stuff.

Clive

[bmcecosse]

What gearbox do you have - and what tpm is the speedo?

[sixdogsisback]

The engine and gearbox is 1098, but the diff is 948 4.55/1. I believe the correct speedo for this axle is SN4407/00 TPM 1504. this is the gold speedo which was in the car when I bought it. I have just ordered a new cable from Bull Motif at £7.50 but its nearer twice that price with postage and vat- bit of a con really, like everything else these days.

[bmcecosse]

Yes - a 1504/1508 is fine with a 4.55 final drive. But really with a 1098 engine you should be chasing up a 4.22 or even a 3.9 final drive. My 1098 is a bit warmed up - and it runs a 3.7 very nicely. Now test all the other speedos with that drill and see if they work! Your cable cost VERY much less than the reconditioning of the speedo that you were contemplating.....

[sixdogsisback]

Yes you are right. I only really need 4th gear and reverse with this setup. I did not configure it and I would like to fit a lower ratio diff, but it's the dreaded oil leaks on the half shaft flanges which frighten me. Now that the MOT is not mandatory on my car, I think I've finally cured the persistent leak on the nearside and I'm very reluctant to disturb it again. though the real problem was the bearing oil seal which was giving me trouble. I bought several oil seals from a different supplier and it seems to have done the trick, so I have the other seals as spares now. I am convinced that when these cars have been stood for a long period of time as mine was before I bought it, the axle casing rusts at the top where the oil has drained off and the now pitted surface wrecks the new oil seals, or the seals don't work properly on the pitted surface. I don't know what the answer is. I don't do large distances though and most of my Minoring is on short runs on slow roads, so the diff is not too much of a problem.

I'll try the new cable with the original bronze speedo and see what happens. It's a question of elimination of all possible causes. though it points to a drive problem as the mile recorder had stopped working also, I particularly took note when I noticed the speedo was sat at zero

Clive

[bmcecosse]

Aye - for short runs/small use the final drive won't matter.

[sixdogsisback]

I was just trying to work out what readings i should get with the cordless drill driving the old gold speedo. The drill is quoted as 400 rpm slow speed and 1300 fast speed. If the speedo is 1504 revs per mile, at 60 mph it would be 1504 rpm. So I should get about 16 mph at 400 rpm and 52 mph at 1300 rpm. I got about 25 mph and 45 mph for the two drill speeds, but it was a bit inconsistent. Then you don't really know what speeds the drill is rotating at. The state of the battery would alter the maximum speeds. The only thing is to fit the speedo back in with the new cable and see what happens. I did notice copious amounts of grease or congealed oil coming from the drive hole, which may well have loused up the speedo.

Thanks for all input , suck it and see!

Clive

[Trickydicky]

Hi,

If it is any help, Practical Classics ran a article in August (I think) on how to do a basic overhaul and stripdown of a speedo. They seemed to suggest that some problems were simply old oil and grease gumming up the workings.

Richard

[sixdogsisback]

This sounds interesting. I've tried to find this article on the Internet, but I expect they want money out of people. Do you know how I can get hold of the article?

Clive

Hi,

If it is any help, Practical Classics ran a article in August (I think) on how to do a basic overhaul and stripdown of a speedo. They seemed to suggest that some problems were simply old oil and grease gumming up the workings.

Richard

[Trickydicky]

you have a PM

[charlie_morris_minor]

i have a pdf document about stripping a speedo..more than happy to send it out to anyone, just drop me your email address in a PM. The document was written by a student as a project and is not covered by copy right if anyone is concerned.

[Windy Pig]

if it is not too cheeky, I'd be interested in this, my speedo died, pretty sure the damper had gone as it was whirling around like a loon, I got lucky, and found a second hand that was the same and worked, but if I can get the old one working I'd happily donate it, as I know how expensive new and reconditioned can be.

[bmcecosse]

The spring must be broken - and the stop broken off! Plenty of speedos for ~ £5 - don't worry about it too much.......

[sixdogsisback]

Where is the best place to start looking for a speedo for £5? they seem to be wanting £30 on e bay. I think it would pay to take a small cordless drill with a squared off bit around to look at these speedo s in future.

I have three faulty speedo s at present. I fit a new cable as you suggested and one of the speedo s now works very well, needle is rock steady, no waving about, but the gears driving the odometer are stripped, the mechanism being seized. The speedo which was fitted when the problem developed still acts erratically despite cleaning and lubricating. I think the bearing on the rotating disc is worn and the driven disc catches the aluminum disc from time to time, dragging it round until the hairspring pulls it back. The third speedo also has stripped gears to the odometer also, but in this case, it's the brass worm gear, not the pinion, as this has a metal pinion, not tuffnal, as the other one has. All good experience I suppose. One thing I've learned, I can swap the cases around to suit the lamps fitted to my car. Some don't have an indicator lamp hole. One of the speedo s had a bit of mastic like filler stuck across the aperture of the lens on the oil pressure warning lamp and it was almost impossible to see the lamp. Now why would anyone do that as opposed to just removing the wire from the sensor to fool a buyer, or removing the bulb from the lamp?

Clive

[bmcecosse]

Just be patient on ebay.... Or ask on here of course. This one 99p at the moment..... post extra of course - I can't help that bit!!! http://www.ebay.co.uk/itm/Classic-Mini- ... 416ccef57e And this one slightly over £5...... http://www.ebay.co.uk/itm/Smiths-Speedo ... 27cbe92303 I agree - though, prices do seem to have risen of late!!
And this one at £6 at the moment....http://www.ebay.co.uk/itm/AUSTIN-MORRIS ... 3f1db2d1a3