Classic/Antique Car Repair: speedometer 1959 Cadillac, speedometer shop, speedometer repair

Question
Hi there. I have speedometer problems on my 59 cadillac series 62 with cruse. The speedo stopped working last year. I unscrewed the cable from under the car and the cable spins  but the needle does not move. I have the owners manual and tried to drop the dash but it would move to get acess to the back of the speedometer. What am I doing wrong as I'm new to this.

Answer
This problem is probably going to require a visit to a professional speedometer shop to get it fixed.

There are some checks you can make:
1.  If the cable is connected to the speedometer head, and the odometer works, but the speed indicator doesn't, (or vice-versa) the problem is inside the instrument, and fixing that is beyond the abilities of anyone but an experienced speedometer repair technician.  Take the car to a speedometer shop and let them take care of it.

2. If neither the odometer nor the speed indication work, the problem might be inside the instrument, or it might simply be a cable problem.   You need to verify that the cable is good, and that it is fully inserted into the back of the dash instrument.   

I can't give you step by step instructions for removing the speedometer instrument, as I don't have the mechanics shop manual for your car.   I certainly would not advise doing that unless you have determined that the problem is inside the instrument.  Once you do know that, you can obtain the shop manual and do it yourself, or simply take the car to the speedometer shop and let them do the whole job.

To verify that the speedometer cable is good, and fully inserted into the instrument, you only have to reach up behind the dash and unscrew the cable from the speedometer and watch the end of inner square part of it while you move the car - it should rotate as the car moves. If it doesn't, there is a problem with either the cable, or it isn't fully inserted into the transmission drive gear under the car, or possibly the drive gear in the transmission has failed.

If you decide to get the shop manual, contact any of the automotive literature dealers for one.  I use www.faxonautolit.com, but there are many others - listed in Hemmings Motor News under "services offered".

Dick