47 Speedometer question

[47SixtySpecial]

Hello, The speedometer on my 47 60S is jammed up. As I don't have a master parts book, I was hoping some kind soul with such, or even better experience working on them, can tell me which are interchangeable. My guage face and indicator are in excellent condition. It would greatly assist me in expanding my search for a spare.

EDIT: A kind gentleman sent me the part number - 1566566. Speedometer from 42, 46 or47 - 60S or 62 series. I still think that the internals are likely the same for other years, just a suspicion.

[35-709]

Since the old one has to come out anyway, why not have your original rebuilt?  There are several excellent speedo, clock and gauge rebuilders out there that can make your speedo as good as new.

Instrument Services is just one of several.
https://www.clocksandgauges.com/ 

[47SixtySpecial]

I prefer to do it myself. For me, it is a part of the enjoyment of the whole process. My car, that I found about 10 days ago (after more than 2 years of searching), is an original unmolested survivor. Other than a repaint that looks about 40 years old. I intend to leave it as is as much as I possibly can. As they say, "It's only original once."

[Jeff Rosansky CLC #28373]

Pretty car.
Jeff

[Steve Passmore]

Super car. When you say 'Jammed up' do you mean it just isn't working?  Most problems with speedos are related to the cable being broken or tangled.

[47SixtySpecial]

It made a screeching/grinding sound, and almost instantly snapped the cable. I unscrewed the shroud from the back of the speedo, pulled out the cable. Inserted the end in and it won't turn. I haven't pulled it out yet to get a closer look. It must be a broken gear or gear shaft.

[Oliver Betker]

Hello
I have a question on your tread. My speedo is working, so the cable has to be ok, but the odometer is stand still for years. the other way round would be more Logical then this.
Can anybody give an adwise?
Sorry about my English!
Oliver

[47SixtySpecial]

Hello Oliver. Which year is your car? I can probably help you if it is in the 36 - 48 range of cars.

[Oliver Betker]

Hello Joe,
my car is from 1946 and in a very original condition.
Series 61 coupè
I would enjoy to find the fould in the first way, in the next to replace the item.
Sorry about my English, I am from Germany and not well trained!
Regards

[47SixtySpecial]

You english is fine Oliver. Prefieras hablar en español o inglés? Yo hablo inglés y español también.

The speedometers in these cars have two drives. One, is a magnetic drive which turns the speed needle. The second is a shaft that is geared from the cable drive out to the odometer and trip odometer. It may be that someone has removed this shaft. Does the trip odometer work?

They way this works, in behind there is the connection for the cable from the transmission. This connection has a gear, that drives the shaft that connects the motion to the front of the speedometer. On top is the odometer and below is the trip odometer. One end of the shaft, in back has a regular gear, the front of the shaft has a worm gear.

If this is hard to understand, tomorrow I can send you some pictures to show you the inner workings. This may help you better to understand.

I have determined, that these inner gear drives are similar among many years of this era. You do not need to find an exact matching year. You just need the technical skill to mix and match the components to get a working system.

[Oliver Betker]

Hello Joe,
thank you for the detailed Information. A couple of pics would be fine and underline your discribtion.
If it makes not too much effort, I am looking Forward for it.
Could you also Show how to open the speedometer, I haven't disassembled it until now and the old once I have known are like riveted with the brezel. But this are old types of european cars.
Regards Oliver

[Tom Boehm]

Hello Joe, Nice car. I tried to look up your question but my 1935-1949 Cadillac parts book does not have speedometers in it at all. At the pertinent pictures it said "speedometer, N.L." as in not listed. Hopefully someone else with a different book can find it.

[47SixtySpecial]

I got it out and cleaned the rear drive with solvent... flushed it out with WD40 and then lightly oiled it up. Works fine now.