Speedometer works but not odometer


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By Rusty_S85 - 5 Years Ago
On my '56 Fairlane I just did my oil change and noticed after a decent 2 mile drive couple weeks ago where I found a horrible spark knock and transmission falling out of gear, I realized my odometer is still sitting at 55,000.5 but I have photos from before the car was driven that is reading 55,000.6

Im curious what could cause this?  I don't know about the '56 gauge but I know newer speedometer gauges uses a worm gear to spin the odometer while the needle moves through magnetic interference as the cable spins the assembly which spins the odometer worm gear.

Im wondering if this is something that could be simple to fix or if it would require sending the whole unit out.  if I send it out then I would probably pay for a full restoration to make it like new.
By Florida_Phil - 5 Years Ago
You are correct.  The cable from the transmission that screws into the back of the speedometer drives both the speedometer and the odometer.   If you remove the speedometer from the dash you will find the problem.  In a '56 Ford, the mechanism is entirely mechanical and fairly simple.  You should easily see the problem once you have it out.  Some of the parts are plastic.  You either have a stripped gear or something is disconnected.
By Rusty_S85 - 5 Years Ago
Florida_Phil (2/10/2019)
You are correct.  The cable from the transmission that screws into the back of the speedometer drives both the speedometer and the odometer.   If you remove the speedometer from the dash you will find the problem.  In a '56 Ford, the mechanism is entirely mechanical and fairly simple.  You should easily see the problem once you have it out.  Some of the parts are plastic.  You either have a stripped gear or something is disconnected.


Thanks for the reply, I need to pay attention to it next time I drive the car, if the tenths is turning then it might be the tenths counter to the rest of the odometer is broken if that is the case then I will source a old used speedometer off ebay cheap and rob the tenth counter
By Rusty_S85 - 5 Years Ago
Know its been a long time since this update but I drove the car today for about 20 miles using Low to get the car moving from a stand still since I am still awaiting for the old timer to get space to take it in for a transmission rebuild.

On the speedometer I see the tenth mile spins, I was watching it roll up to 9 then back to 0 numerous times but the first mile does not move.  It looks like the first mile wheel is the one that is preventing my odometer from working.

I have two choices I can take and pull it apart and move that wheel to the last but then I wouldn't have it showing the ten thousand mark.  Other option is to source a set of odometer wheels from another speedometer and transfer them over.  I found a few '56 speedometers but I hate to spend $120+ for a speedometer just to rob the odometer out of it to put in my original unit.

Search continues how ever to find a odometer by itself or a reproduction set of odometer wheels for a '56 speedometer.
By paul2748 - 5 Years Ago
You could always send it out to get repaired.  Try Williamson's in Arkansas.
By Rusty_S85 - 5 Years Ago
paul2748 (4/21/2019)
You could always send it out to get repaired.  Try Williamson's in Arkansas.

Thanks, I sent him a message.

Ideally I could do the work myself if I could just source the parts.  I looked online it looks like pulling the odometer assembly out is quite straight forward.  I will just await a reply and see what they say.  All I know is I don't want to restore anything just fix it to be functional.  I just like to know what miles I put on to keep up with my service.  Once I put the car down to strip it to the bare frame for restoration I will be sending all my gauges out to be restored to new condition or source NOS units if possible.  Hate to do that to the speedometer now and have it aged by time I reach that point.
By Florida_Phil - 5 Years Ago
I have worked on many speedometers over the years.  The odometer tumblers in your car are most likely plastic. There is a long tooth on the tumblers that turns the next higher tumbler.  One or more of your tumblers is broken or gummed up.  If you have some mechanical ability, it's not that hard to take them apart and find the problem.  I was an office machine service technician in my youth, so it was a piece of cake for me.  Go for it.
By crown55vic - 5 Years Ago
Phil,  I, too, worked on office equipment in my career.  Mechanical adding machines, cash registers, accounting machines and bank proof equipment.   Then moved to electronics and POS, computers, and servers.  Worked for NCR from 1963 to 1995 then IBM from 1996 to 2012.  Enjoyed the mechanical more than the electronic.  Did you have a similar career path?
Ben.
By Florida_Phil - 5 Years Ago
How about that!   Yes.  I worked for the Burroughs Corporation from 1966 until 1970.  Started out working on mechanical adding machines.  Went to Detroit to be trained on the Burroughs Sensimatic accounting machine.  I left Burroughs in 1971 to start my own company which led me into computers, software, networks and the Internet. I retired in 2000.  My son still runs my company.
By Lanny White - 5 Years Ago
Florida Phil, I have just read this thread and, I too, have speedo issues with my '54 Merc.  It is frozen and I am wondering what the rotational direction is looking from the back (under the dash) side.  I don't want to turn it the wrong way and break something.  Also, what procedure(s) should be used to free it?
By Florida_Phil - 5 Years Ago
I am sorry, I don't remember.  The Ford odometer is a pretty simple mechanical device.  Don't force anything and you should be able to see the problem.  Back in the day, lots of people made a living turning them back. 
By Gene Purser - 5 Years Ago
The input shaft will turn either way. It has to because the cable turns backward when the car backs up.