Speedo Cable Routing - 1934 and 1935 Cars

Old Fogey UKOld Fogey UK Posts: 1,014Expert Adviser
Please may I have some guidance, please ?
Out in my '34 last Sunday, my speedometer needle suddenly dropped to zero.
The speedo has been rebuilt recently and had a new cable at the same time and the set-up has been working OK.
Investigating the problem, I found the cable all chewed up at the transmission end with no damage at the dashboard end.
The output on the gearbox turns freely and I can turn the speedo needle by hand using the spigot on that end of the cable.
This is the third time in my ownership of the car that I've had a cable fail in exactly this way and the only reasons why that I can think of are -
1. I'm using the wrong cable.
2. I'm not routing it correctly and that's causing it to kink and jam up.
I've been using a Ford 1932-48 (passenger car) cable which is the same length as the original equipment and is listed as a substitute in interchange manuals - is it the correct type ? If it isn't what type should I use ?
Please can someone show me the correct route for the cable (I've simply been putting it where it seems logical for it to go) ? 


  • ken1962ken1962 Posts: 343Member
    Usually it chews up when it has a binding issue ie a slight bend that restricts rotation at certain speeds. You are correct that you need to find the best route. Hope you find some help. 
  • sidevalvesidevalve Posts: 75Member
    I have just had exactly the same issue with my 1954 Ford Prefect, ad I think that what Ken says is right - the routing seems to be key, and if you leave a too-tight curve anywhere it jams and breaks
  • Old Fogey UKOld Fogey UK Posts: 1,014Expert Adviser
    Routing the speedo cable in a '34 is like trying to find a way out of the Minotaur's Labyrinth !
  • sidevalvesidevalve Posts: 75Member
    Same with a 54 Prefect! I just broke a brand new one without even driving out of the yard!
  • Old Fogey UKOld Fogey UK Posts: 1,014Expert Adviser
    Spent a few hours web surfing and it seems that 34 - 37 Hudsons and Terraplanes may use the same speedo cable as a 1935 Plymouth PJ and a 30 - 34 Ford.
    The inner cable is 61-3/4" and the outer is 61".
    Can anyone tell me if this is actually correct before I mess up an inner cable repair kit ?
  • ToddhToddh Posts: 387Member
    Is your car right hand drive?  If so, obviously the Speedo is on the right side as well but the Speedo cable connection at the trans is on the left side.  

    On my 34 (left hand drive) the Speedo cable comes through the firewall directly forward of the speedometer output. It is secured through a rubber bushing in the firewall.  Then it heads underneath the body along the left side of the transmission until it connects on the transmission tail.  It goes through a clamp on the frame crossmember that supports the transmission.  

    I’ll have my car out and about this weekend and I’ll take some pics
  • ToddhToddh Posts: 387Member
    I just measured an NOS one I have.  61 3/4” overall and 61” for the housing

  • Old Fogey UKOld Fogey UK Posts: 1,014Expert Adviser
    Thank you very much Todd.
    I'd really appreciate a few pics, please.
    My car is LHD, having been bought by me from a HET Club member in Michigan.
    I'd be particularly interested to see a pic of the clamp you mention, please, as it's missing on my car.
    I had assumed that the cable was routed through the little flute in the top edge of the removeable floor panel - there's another one on the right hand side that I thought Hudson put there for the cable on RHD cars.
    From what you say, I've been getting that wrong !
  • ToddhToddh Posts: 387Member
    My mistake.  No clamp. Guess I was thinking about the 46 shift cable.  
  • ToddhToddh Posts: 387Member
    Here’s where he cable comes out of the firewall

  • Old Fogey UKOld Fogey UK Posts: 1,014Expert Adviser
    Thank you very much, Todd.
    I can't use that hole in the firewall because it takes a load of wiring through it and rerouting it all would be a complicated job.
    It looks like I'll have to use the groove in the floor panel again to route the cable.
    I've been under the car this morning and I can get it up through there to the back of the speedo without kinking it or bending it into a severe curve.
    The problem seems to be at the transmission end where I'm left with a lot of cable length and I'll need to put a loop in the cable to accomodate that.
    I'm posting a pic of how Jim DiGiorgio did it on his '34 - does this look like your set up ?

  • ToddhToddh Posts: 387Member
    edited May 22
    yes but mine is tighter due to routing through the hole in the firewall.  The Speedo cable terminates at the end of the transmission as shown in your pic
  • BigSkyBigSky Posts: 1,039Senior Contributor
    I was just cleaning mine & re-installing it this past week & I found something interesting.  When I went & tighten the ring behind the speedometer to snug, I could NOT spin the transmission end at all. When I loosened the ring a turn or so behind the speedometer I could then turn it at the other end (trans).  Not sure what to make of it but I thought it was unusual.  Food for thought, maybe pull the trans end & spin it to make sure it’s not bound up before you wrap it all up.  If I recall correctly, it spun counter clockwise to get the speedometer to show a speed.  I just used my fingers to spin it as I still have the trans cover off from my clutch, trans, cross shaft, etc repair!
  • Old Fogey UKOld Fogey UK Posts: 1,014Expert Adviser
    Thank you, Todd, for confirming that.
  • Old Fogey UKOld Fogey UK Posts: 1,014Expert Adviser
    Thank you, Big Sky, that's very interesting.
    In the past, I've always tightened both ends very snugly and left it at that but I will try your test when I install the repaired cable.
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