1972 cluster

[Roger Zimmermann]

For about one year, I bought a '72 Coupe de Ville which is now refurbished by Brian Faull. I did not expected that it would take so long to get the car, my fault by not asking enough!
As I'm living in a country using metric dimensions, I came across a speedometer in km. The cluster is coming from a car imported by GM Suisse, therefore in km for the odometer and speedometer. Unfortunately, some dust collected near the stem for resetting the trip odometer. In the fifties, il was easy to take out 1000 screws to clean that, but here, the plastic window is attached to the body with heated pins. As I cannot install a dirty cluster, I milled and drilled the pins until the plastic window could come out.
The window will be attached by screws as there is a provision for that.
What I found may be interesting: there are 2 part numbers on the body: 6493962 for miles and 6493963 for km. It's the same body for both applications; on the clusters for export cars, a strip with km was glued over the scale in miles. As those numbers are cast in relief, a small void can be seen between that strip and the body. No, I will not take the strip out to verify my theory!
Now, I just need the car to install the cluster...

[The Tassie Devil(le)]

G'day Roger,

I have a Metric Cluster in my '72 Eldorado, and the differences are the strip that is covering the Miles, and the Odometer gears that drive the Odometer rings.

What would you like to know?

I stripped mine down completely, and have lots of photos if you are interested.

I believe mine originally came out of a '73, but I used the best of both units.   I was tempted to open up the odometer slot to reveal the decimal roller, but decided against it, as the trip meter is working well, and has that feature.

Plus, before I installed it, I adjusted the hair spring so that the needle would read correctly, which it does.

Bruce.

PS.   I did notice the casting number differences.

PPS.   It was a cheap and nasty way of converting the Imperial Cluster to Metric.

[Roger Zimmermann]

Hi Bruce!
Thanks for your comments. Indeed, the cluster for 1971 to 1973 is the same for all vehicles. In fact, I have no question, it was just an information! When I know the correct mileage on my car, I will calculate that value in km and adjust the odometer accordingly.
Why did you adjusted the hair spring? the speedometer was not correctly calibrated?

You are right about the cheap way to convert a miles cluster to km; I suppose that the volume of exported cars in km was too low to warrant a separate body.

[The Tassie Devil(le)]

I re-calibrated mine because, as you know, all factory speedos read up to 10% fast, and I wanted mine to be correct.

I used a Mechanical Police Special speedo and ran it in parallel with the Cadillac one, and using a battery drill, got the metric one to perfectly match the Police one.   The Police one was used way back when when the Police cars weren't using corrected speedos, and were operated in conjunction with the vehicles' speedo cable, and had a needle stopping button that could be pressed to show the offending motorist their speed.

Bruce.

[Dan LeBlanc]

Boy, I would love to find one of these for my 70.

[The Tassie Devil(le)]

Probably wasn't a necessity before 1971 as maybe other Countries didn't start mandating Metrification of speedos in imported vehicles as a requirement for registration.

I know that when the Australian Design Rules (ADR's) came in in 1969, the whole items required for registration started to get right into stuff.

The early items weren't that bad, but it became mandatory for Lap/Sash Seat Belts, then over the years, things got stricter with Retractable mechanisms in 1974 for front seats, then later included rear seats.

One reason I like the '72 Cadillac is that it has features that I wanted, and as the commencement date of build was late 1971, I needed to get one built before the 1st January 1972.   Mine was built in October 1971, and therefore I don't have to change the colours of the Indicator lights, or separate them from the brake lights, and a raft of other stuff.

Bruce.

[bcroe]

I want my gauges accurate as well.  Usually pull the tank and rework
the float so the gas gauge can be believed.  Most speedos read high,
can be re geared to be far more accurate. 

I have checked the speedo on a reversed drill press.  A stop watch
on the odometer will allow calculating the actual speed, as opposed
to that indicated.   Once these agree, I take it on the road and
compare the odometer to some country road I have previously
very accurately measured. 

A Km/hr cluster can be made to read out miles/hr, and vise versa
by drastically changing the speedo cable gearing.  Not happy with
an 85 Mi/hr on my 79, I got a Canadian cluster that goes to 140
km/hr.  With special gearing, it now goes to 140 miles/hr.  Seems
to me any readout should cover the entire possible operating
range, with accuracy.  Bruce Roe

[The Tassie Devil(le)]

Down here, we have some highways marked with a measured 5 Kilometer section marked with signs for each Kilometre.   Motorists can then simply check their odometers against the sign posts, and using a stop watch, calculate their speed.

But, these days with the accuracy of GPS', it is simple to check.

Bruce.

[Roger Zimmermann]

OK, Bruce, thanks for the explanation! As I don't have a mechanical police speedometer, I will leave it that way...Did you know that speedo in US cars are now relatively exact? My past 2000 DTS showed the right speed, as well as my 2011 DTS. So I can add 3 to 4 km/h to the posted limit and still be under the speed at which you get flashed...

[The Tassie Devil(le)]

...Did you know that speedo in US cars are now relatively exact? My past 2000 DTS showed the right speed, as well as my 2011 DTS. So I can add 3 to 4 km/h to the posted limit and still be under the speed at which you get flashed...   

Yes.   These days of on-board computers and diagnostics, along with GPS and instant fuel consumption figures, the makers have had to get rid of the original reason for the overspeed reading that they HAD to make things accurate.

I even had one guy try to explain that the police were wrong because he was driving according to the speedo.   But, what convicted him apart from the speed camera, was that he had fitter larger diameter wheels and tyres, and didn't realise this affected his vehicle speedo.

Bruce.