Noisy sticking speedo head


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By oldcarmark - 16 Years Ago
The speedo in my 56 is still acting up even after the cable replacement.It works MUCH better as far as the needle doesn't jump up and down and runs at a steady number on the dial.However the head is noisy and every so often the needle jumps way up for 10-20 seconds.I have the head out and the noise is in the main shaft where the cable hooks to and drives the magnet not in the gear setup for the odometer.Should I try a couple of drops of oil or is this not a good idea?I could take the whole thing apart by removing the rivets that hold the face on and disasemble from there and use very small machine screws and nuts to replace the rivets on reassembly.Anyone else repaired their speedo for this type of problem?Any input appreciated! 
By 55Birdman - 16 Years Ago
Mark, My TBird did the same thing. I just replaced everythiing because the new cable didnt cure all the problem.
By bergmanj - 16 Years Ago
My 55 Crown had a similar problem (and, I've worked on several others in the past): You can take it apart; but, be very careful!  Generally, that noise and the needle jumping is caused by a dry bushing internally to the speedo.  The only way to get to it is by taking it apart: it's a support bushing under the "motor" (a funny-looking 1-1/2" diameter? flattish-round cannister that is magnetized).

After 53 years, it deserves some tender loving care!  Solvent-clean (MEK, etc.; but, DON'T get any solvent on any of the plastic gears, guage face, etc.), then re-lube with a very light machine oil & you'll likely be all set for another 50 years. You may also want to carefully lube the odometer gears & bushings.  If you're mechanically-inclined, you also have the opportunity to re-set the odometer, if desired; though, to some people, that might be "cheating".

Thanks,   JLB

By oldcarmark - 16 Years Ago
Thanks for the help.I would have liked to take it apart and give it a good clean but I settled for a little machine oil using the straw on my oiler.Dripped a couple of drops and let the head sit overnight with the input side down.What a difference.No noise and the needle hardly flickers at all.MG Cook is waiting for a replacement cable for his 55.It would be worthwhile to have a look at the head while waiting.When I turned the input hub with my fingers I could hear the noise and feel the tightness in the bushing.A little oil makes a big difference after 50+ years.The head on mine had been out before.Couple of mismatched and 1 missing screw.Original speedo I think-dated Nov 2 1955 about 2 weeks before the car build date.I did find a name penciled on the mounting plate along with I presume the repair work order #. Not a great mechanic working on it.Missing screw and the brackets to hold the main wiring harness missing.Made a couple of new ones.Thanks for the suggestions.
By MG Cook - 16 Years Ago
Hey Mark,

How hard is it to get this out? I would definitely like to have mine working properly when I install my new cable.

By oldcarmark - 16 Years Ago
Hello MG! On my 56 I just disconnected the cable and removed the 4 screws that hold the head in place from behind(under) the dash and comes right out.Didn't need to disassemble the whole instrument panel.Now I know the 55 is different speedo but maybe someone on this site has the shop manual or knows how to remove easiest way.The second respondent to my question would know from doing his 55.
By bergmanj - 16 Years Ago
Hi. Just back from long weekend off.  The '55 head comes off similar to the '56 described above (I don't remember exactly - been several years - but, relatively easy, as I recall).

JLB