Re: odometer issue - 1937 Packard 115C sedan

Posted by HH56 On 2014/3/30 22:45:03

Nothing you can do without taking the speedo out of the dash cluster and open it up to find the problem.

The cable drives the main input shaft of the speedometer. That shaft contains a worm gear for the odometer drive and terminates at the magnet which induces the eddy current in the cup for the speed portion. As you surmise, since that portion is working, the problem is most likely in the secondary drive to the odometer.

The worm portion drives a spur gear on another shaft and depending on the complexity, can have one or two more shafts with gears to change direction and revolutions before it reaches the number reels. I don't know if 37 had the trip odometer. If it does, you may be lucky and find that reset movement has stuck and disconnected one of the shafts at a drive point.

Another possibility is speedo was jarred and one of the shafts or bearing points was moved enough a shaft fell out of position and the thin spur gears have lost mesh.

More likely the lube has completely dried freezing a shaft at some point. When that happens the usual result is one of the shafts is twisted or damaged or a gear is stripped.

If you find either condition, then a new speedo or repair at one of the instrument shops is the option.