Speedo / Tach / Gauges: 1955 speedster tachometer problem

[dan giroux]

Does anybody have any tech articles or information on how to trouble shoot my tachometer?? Any info would be appreciated. Dan Giroux at kibits3@aol.com

[bezhawk]

All of the Stuart-Warner pulse motor speedometers are just a heavily damped volt meter. The faster the pulses, the higher the average volts.
Usually the gauge is good, and the connections or the brushes in the sending unit go bad. I would check the sending unit first for worn or sticky brushes. Many good hardware stores have replacement brushes for power tools, and sometimes you can find a close match.

[JoeHall]

I have worked on a few 56J tachs, which are basically the same. The connecting harness is most always brittle, with rubber chunking off and leaving bare wires. With a soldering iron, you can renew yours with a piece of round electrical cord, used on any appliances. It is a dead ringer for the OEM cord. Also, you can disassemble back side of the tach head, and put some light, i.e. 3N1 oil in strategic places. As Bez mentioned, the sender is fairly easy to work with, long as the body is not cracked or chipped in the wrong places. It is imperative that it fit correctly, lest the distributor cap can become misaligned with the rotor, then it could break the rotor or destroy the cap.

Those tachs are simple, durable and accurate. I have never had to repair the one in the 56J, but did re-new the harness. As for accuracy, the 56J's tracks right along with the electronic tach in my timing light.

[64V-K7]

You used to be able to make brushes from the anode in a "D" battery