C2 Gauge Restoration - New Life For Old Gauges

Tachometer mechanisms are also fragile. The wound spring on this one is broken, which will cause the needle to not move.

Fuel, water, and electric oil-pressure gauges have a tiny winding inside that moves the needle. If you hook up the gauge wrong or improperly test it, the winding will fry.

After the gauges are disassembled and evaluated, the faces get stripped. If they have rust pits, they're primed and sanded until the pits are gone. The final coat is the correct shade of black, in the correct gloss, and then new dials and numbers are screened onto the faces. (The process is proprietary, so we can't show it.)

Odometers and trip odometers all get new numbers, in the correct color and the correct font; Corvettes changed fonts and colors a few times during the mechanical-gauge years.

This isn't the Corvette speedometer, but it illustrates that every component is thoroughly scrubbed and rebuilt before the parts all go back together.

Once the gauges are reassembled, they're tested and calibrated.

Speedometers and tachometers are calibrated on special equipment. Tachometers are mechanically adjusted, while speedometers are magnetically adjusted.

The gauge housings are chromed cast metal. "They almost always clean up very well, without having to be replated," AutoInstruments owner Gentry Zentmeyer told us. "They rarely have any pitting, so they don't usually need to be rechromed." The factory paint is chemically stripped.

With the paint stripped off, the instrument housing looks naked. Whatever is "chrome" on the finished cluster-such as the gauge bezels-is masked off, then the background is painted in the correct shade of black. When the tape is removed, the panel is black and all the bezels are chrome, even though it's all one cast piece.

The unseen portion of the gauge housing (where the instruments mount), is thoroughly cleaned. This piece usually doesn't rust, and fading isn't an issue, but if it's a flood car or a particularly bad piece, it will be also stripped and painted.

Unlike almost every car in the '60s, Corvettes used glass lenses instead of plastic. Adhesive-backed foam pads were originally installed around the edge of the glass, but they've long since dried up and turned to dust. AutoInstruments polishes the glass and installs it, along with fresh bumpers.

Here's the restored instrument panel, concours-correct and ready to run. Original electric tachs set up to run points-type distributors won't work with modern electronic ignitions, but AutoInstruments can convert both electric and mechanical distributor-driven tachs for compatibility. The company can also change the redline marks for big- or small-block applications, or a different year.

Clocks have a set of breaker points, just like a distributor (shown here being spread apart). As on a distributor, when the points burn out, wear, or stick together, the clock stops working.

AutoInstruments uses a modern quartz-movement clock action to replace the original points-type.

The restored clocks are hooked up and run for 24 hours, then calibrated to ensure accuracy.

Though the instrument cluster is cast metal, there are plastic chrome parts on Corvettes; AutoInstruments restores and replates them to original specs as well. "It's real metal chrome," Zentmeyer tells us. "It will carry an electric current, just like the original pieces."