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Speedometer Problems: I need your help and advice.

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  • Speedo/Tach/Gauges: Speedometer Problems: I need your help and advice.

    As most of you know, my car is a ’55 President State Sedan. After finally finding the source of an oil leak I drove the car down the road to test it and the speedometer was reading about 2MPH.

    I searched prior threads on replacing the speedometer cable. There was good information concerning lubricating the brass cup at the back of the speedometer, etc. I removed the speedometer from the dash did some tests as outlined below but still no speedometer.

    After the speedometer was removed, I pushed the core as far into the shaft as I could and tried to twist it. It would only turn about ½ turn and I figured the core was not broken and that the pinion inside the tranny was making contact with the gear.

    I pulled the core out of the shaft and measured it. It was just shy of 47” to the little stop near the back of the speedometer. The parts book calls for a 47” shaft and core so that was close.

    I then cleaned out the small brass cup in the back of the speedometer with compressed air and a small wire. I then filled the cup with air tool oil. From the picture I took it appears as if there is some sort of mesh under the tiny hole.

    I chucked the tranny side of the core into a battery powered drill, put it in reverse and ran the speedometer up to 80MPH. There was no jumping of the needle and it responded to the speed of the drill smoothly.

    I greased the core again as I had cleaned and greased it during the rebuild.

    I put the speedometer partially back in the dash and ran it down the road. No reading.

    I removed the tranny side of the cable. The pinion looked like it was contacting the square end of the core for about ¼”. I had my wife, Pat watch the speedometer as I rolled the pinion teeth on my hand to get it to rotate fairly fast. Pat said the needle rotated up the speedometer as I was doing that.
    The part number, 527689, is correct per the parts book for an AD with 3.54 rear end. It has 23 teeth. The diameter of the pinion teeth is .920.

    I am sitting here typing this post and wondering what in the world is keeping the speedometer from working. I have established that the needle will move when the pinion gear is turned. Therefore I am thinking the problem is at the tranny side. The teeth may be worn down so that they are not contacting the gear inside the tranny. I hate to do it but I am thinking about taking the speedometer back out, replacing the tranny side of the cable into the tranny and driving down the road to make sure the core is turning. Maybe the gear in the tranny is broke? I certainly hope not. If anyone has a suggestion as to what else I can check out or what I may be doing wrong I’d appreciate your help.

    Charlie D.
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  • #2
    did you tranny shifts normal through the gears?
    I just had the problem at my DG250, that the shaft of the govenor has been torn of. The speedo gear in the tranny is connecte to this shaft.
    I can take a few pics of the gear and the shaft tomorrow.
    If you need advise for the replacement, I can give you an instruction.



    • #3

      Let me do the test to see if the speedo gear is not turning. The DG250 seemed to operate normally. Of course that entails a hard shift into direct drive the first couple of times then it smooths out. If mine has the same situation as yours I will be very grateful for instructions.

      Charlie D.


      • #4
        Is that Cable original to the Car or working before work was done to the Car?

        The reason I ask is, I have only seen that type of Cable end with the "Bullet" having an "O" Ring, on much later Studes. than 1955. Earlier Cars had a cork gasket under a shorter Cable end.

        I am more familiar with Standard Transmissions so that might be the difference, but i really think it is the YEAR of the Cable vs the Car/Trans.. If the Pinion enters the wrong depth, it will not run.
        Second Generation Stude Driver,
        Proud '54 Starliner Owner


        • #5
          I just went through this on my 51. First make sure the speedometer cable is turning. If it is counting miles but not speed, then you know the cable is doing its thing. That is what my car was doing. On my car the cable core was pushing to hard on the back side of the speedometer and was causing the speedometer to not read mph. It about drove me nuts. It would work on the bench, but not in the car. My solution was to loosen the cable nut. I know that’s not really “fixed”, but it works now.
          1962 Champ

          51 Commander 4 door


          • #6
            Disconnect speedo from cable. Drive car. If the cable turns the trans gears and cable is ok. If you spin the speedo and it reads then the cable's too short or it is not engaging the speedo. (It's likely the cable) Best of Luck!


            • #7
              Speedometer is working again!!

              I did the test to check the tranny gear. I removed the speedometer and put the pinion back in the tranny. I held the speedometer side of the cable and back the car up a few feet and then forward in the garage. I could not keep the squared end of the cable in the car from turning so obviously the gear in the tranny was turning. I reinstalled the speedometer and before I got to the end of the driveway it was registering. Ran it a quarter mile down the road and the speedometer was working fine. My only guess is that the square end may have come out of the pinion at the tranny and was not turning it. If it happens again I may adjust the stop on the cable at the speedometer to try to force the cable back toward the tranny.

              Thank you for showing the concern you did as I was stumped. To tell you the truth I am still rather stomped as I do not know any particular thing that I actually changed on the setup to make it work again.

              Thank you, guys!!
              Charlie D.


              • #8
                Chuck Tubens just did a full rebuild on the DG250M in my '55 President State and noted I had removed the speedo cable from my speedometer. When he asked why I told him the speedometer had been making noise and the needle was bouncing.
                He explained that the cable only works on the odometer and actually generates an electromagnetic field to power the speedometer portion. I don't pretend to understand how this works but he was pretty convincing. Anyway, he pulled the speedometer and lubricated it. He re-installed it and hooked my cable back up and the speedometer needle was all over the place. He disconnected the cable and confirmed that the cable itself was spinning and then re-connected it. Same thing. The odometer is rolling along just fine. After reading this thread I may try disconnecting and re-connecting it again and see what happens. It's ironic that you posted this at just about the same time. I'm glad you got yours working. I'll let you know if I have the same success.
                Ed Sallia
                Dundee, OR

                Sol Lucet Omnibus


                • #9

                  Thank you for the heads up on the magnetic thing. I did a web search and found something about it. That is pretty neat. I hope yours stops bouncing around. It is also nice to know where one can get the DG250s worked on in case mine ever needs it. Good luck with that President State. I almost always read your posts concerning it as it may well effect a situation I may run into.

                  Charlie D.