What experience has anyone had on repairing speedometers

[hearn]

I have a 1954 Cadillac and my speedometer does not function as well as I would like.  Many years ago when I had the dash out, I attempted to apply some light oil to the speedometer bearing.  I had heard stories of too much oil getting where it was visible so I oiled very sparingly.  Once in a while (usually into a long trip) my speedo needle settles down, but most of the time it makes a clicking sound and occasionally the needle is all over the place.  I have tried to find a way into the needle's bearing from underneath, but to no avail.  I would appreciate any thoughts on this.  Thanks, Jim

[Jeff Rosansky CLC #28373]

Our 55 did that until the cable finally broke. Replaced it and fixed it 90+%. So I would suggest replacing the cable FIRST and go from there. You can access it with the dash in place. I just got a universal one from Autozone.
Jeff

[The Tassie Devil(le)]

I would be inspecting the Speedo Cable, as this is likely to be the culprit.   Should be lubricated, and spinning freely.

And, secondly, if that is good, look at the odometer gearing, as I have found that dried grease on these shafts have caused the gear where the shafts turn the rotation at 90 degrees to go to the odometer head have become worn out, and start to slip.   This also causes the needle to go very erratic.

Bruce.  

[Mike Josephic CLC #3877]

Agree that the speedo cable is the most likely issue.
However, oil or grease should not be used to lube
these.  Instead, graphite or graphite / alcohol is
the best.  Lock-ease is one name for the
graphite / alcohol material.

The alcohol will carry the graphite through the
length of the cable then evaporate.  In that way,
it does not work it's way into the speedo head.

Mike

[Bob Schuman]

NAPA auto parts was able to order a cable assembly for my 49 recently. You just need to know the length and end connections. I'm pretty sure your end connections are 3/4" female thread at the transmission and 5/8" female thread at the speedometer, same as used on many cars for many years.

[fishnjim]

I'm a '53 model and some of my parts don't function as well as I'd like, so maybe need to temper expectations?
Part of the problem is wear.   Replacing the cable might solve but if it's in the trans or speedo end then more surgery.   
Not to muddy the water/argue, but from all I've ever known the speedo cable should be lubed with white grease, not graphite.   They used to sell an adapter to do this job.  I had one but it's gone the way of history.   I'd refer to service manual as referee.   If your's says graphite in '55, then go with it.   
Talk to McVey's, if you have further issues.   They fixed mine.

[Bob Kielar]

Had the same problem with my 55. I replaced the cable but to no avail. What I had to do was pull the instrument cluster out. Then I cleaned all the old hard grease out and relubed. I think I used white lithium grease sparingly on the gears and light weight oil on other parts where needed. It has been running smooth for a couple of years now. If you go to the Mid-Century Cadillac forum and search for 55 speedometer there is a thread there that I started for my repair even a little video. Don’t know why it’s not on this forum I usually post both places maybe I couldn’t figure out how to post the video.

Keep Cruzin,

Bob Kielar

[nixiebunny]

The cable is definitely the first thing to fix.

The speedometer head might have a worn bearing, in which case it will be noisy. The check for this is to feel the play on the little nub that sticks out of the speedometer, where the cable attaches. It shouldn't be too loose side-side. Also, if you spin it by hand and it makes a chattering noise, then it's shot.

I replaced the speedo frame and moving parts in my 1940 LaSalle with one from a 1958 Chevy. I had to drill a hole in the pot metal frame to fit the original odometer shaft into it, but other than that, it was an easy replacement. However, it's running about 30% slow. I need to take it out and recalibrate the hairspring.

Disassembling the speedometer requires some care, so that you don't let the hairspring flop around and get bent.

There are two things to lubricate. I used 0W-20 Mobil 1. Place one tiny drop of oil in the end of the little hole in the spinning magnetic cup where the pointer shaft sits. Also a couple drops in the main bushing, which has a little tiny brass plug on its lubrication port that's on the side of the frame. There's a felt wick in there also.

You can buy new odometer and trip meter assemblies for 63-67 Corvettes from several sources. Those parts may be used to rebuild the odometer, if needed. It takes some daring and a lot of patience.