Toledo speedo over reads considerably but odometer accurate

[2door-toledo]

Hi,

Since getting the Toledo back on the road a few years ago the speedo over reads by a considerable margin, e.g. at 60mph GPS the speedo indicates 80mph. At lower speeds the over read still exists but is smaller.

The car is completely standard. The odometer seems to be very accurate.

Is there anything I can do about this to recalibrate the indicated speed or does it require specialised equipment? Does someone know what could be wrong with it. Speedy Cables have quoted me £170 and 4-6 week turn around time which I'd rather avoid.

I'd like to keep my original speedo. I've been adjusting in my head until now but it would be nice to make it more accurate.

Thanks.

[xvivalve]

First thing I would do is test another speedo' head to confirm that is where the issue is, preferably a known good one...

[cliftyhanger]

Has the gearbox been changed at any point? It could have the wrong drive gear in the box.

[2door-toledo]

First thing I would do is test another speedo' head to confirm that is where the issue is, preferably a known good one...

Probably a good idea. Does anyone have a known good used Toledo speedo for sale? Fitchetts have a NOS one but at over £100 with no intention of using it later I'd rather not go down that route - also not known to be good.

[2door-toledo]

Has the gearbox been changed at any point? It could have the wrong drive gear in the box.

I don't think so, but if it happened, it happened before 1982 when the car was last on the road. It's got the correct DG box and if I recall correctly with a number in the right kind of ball bark as the engine number and commission number so should be original to the car. When I got the car back on the road in 2019 I took it to a chap in Sussex (Pete I believe) who was recommended by the TSSC and he declared it fine and did very little to it, just seals I believe.

Doesn't the odometer being correct suggest it's not an issue with the wrong drive gear? I'd have thought it would make that incorrect, too.

thanks

[Carledo]

To be fair this sounds like standard performance for an early Toledo speedo and the one in my '72 1500 displays much the same degree of error, about 2-3mph over at 30 and 15-18 over (the needle wobbles a bit over 50) at a true 60.

They weren't all THAT accurate when new, though obviously within the 10% each way allowed by construction and use regs. But most speedos in those days flattered the car to a certain extent.

Not being all that picky myself, I just run with the satnav on "display map" all the time and use that if I'm somewhere with many cameras and ignore the speedo.

The fact that your odometer seems to be correct would indicate there isn't a gearing error that needs correcting and all that really leaves is speedo calibration. So you either live with it or bite the bullet! I've dealt with Speedy cables myself, they made me a one-off speedo cable for the Carledo. They do know how to bear down on the pen, but they also know their business inside out. I can't think of anyone better qualified for the job. The 4-6 week timeframe isn't because the job takes a long time, it just takes that long to get YOUR job to the head of the queue!

But here's a thought, back in the days when a following police car "clocked" your speed on a separate specially calibrated speedo atop the dash, those speedos were recalibrated at 6 monthly intervals to guarantee accuracy for prosecutions. Your Toledo speedo hasnt been calibrated in over 50 years, it's entitled to a bit of error!

Steve

[2door-toledo]

Thanks Steve. You're right, it could have always been like that. The speedo in my Stag is very accurate so I just assumed it should be better. Mind you the Stag speedo wobbles a fair bit at low speeds, whilst the Toledo one is perfectly smooth!

I'm sure Speedy Cables are well qualified, I just don't really want to be without the device for 4-6 weeks right now, so it'll probably have to be a winter job when the car is hibernating. Would be nice if I could reserve my spot in the queue and then send it off closer to the time. Oh well.

Thanks.

[Carledo]

Thanks Steve. You're right, it could have always been like that. The speedo in my Stag is very accurate so I just assumed it should be better. Mind you the Stag speedo wobbles a fair bit at low speeds, whilst the Toledo one is perfectly smooth!

I'm sure Speedy Cables are well qualified, I just don't really want to be without the device for 4-6 weeks right now, so it'll probably have to be a winter job when the car is hibernating. Would be nice if I could reserve my spot in the queue and then send it off closer to the time. Oh well.

Thanks.

Well, it probably WAS a bit better when it was new! The speedo works by magnetic induction and several factors can affect it's function, whereas the odo works more like clockwork and has a different set of potential errors. But this accounts for how one can read right and one wrong.

I did have a Toledo speedo with about 41k on it around here and, if memory serves, it wasn't badly inaccurate, at least not enough to comment on, though I did once see it display 85mph absolutely flat out on the old 1300 motor! However, I can't at this moment remember if I parted with it or not, i'll have to have a look! If I still have it, you're welcome to borrow it or buy it for a whole lot less than £100 (like a whole zero less)

If you did that, you could put the substitute speedo in and drive it around whilst your original one is away.

Steve

[ClassicFan]

I Have used John @ JDO Instruments http://www.jdo1.com/speedos.html in the past for speedo calibration with good results, there is even a guide on what is required to check it http://www.jdo1.com/speedo_calibration_1.html