Corvette Distributor Rebuild - Rebuilding The Tach-Drive Distributor

Upper bushing and its grease cavity show wear and solidified grease. Bushings are durable and need no attention over the distributor's service life. Use of proper greases during assembly will preserve the breaker plate and upper bushing. Align the upper bushing's oil hole and the tach drive gear's notch when fitting the new bushings.

Wear points in these distributors are clear. Fortunately, the points, condenser, rotor, breaker plate, driveshaft, shaft bushings, weights and springs, the drive gear, vacuum advance and hardware are still available for this distributor. The tach drive parts are also vulnerable to wear, with parts available in the aftermarket.

Parts like this breaker plate have bearing surfaces and electrical wiring. The bushing on this plate has no appreciable wear. The wire is a ground and shows slight oxidation and corrosion. The corrosion can be eliminated with a quality contact cleaner or baking soda rinse. Driveshafts seldom wear out; however, a replacement shaft is currently available if needed.

Unless the distributor cam lobes have bad wear or scratches, the surface can be restored with a polishing buffer and metal polish. This cam must be smooth, or the breaker point's rubbing block will deteriorate quickly, closing the point gap. Take time to restore shafts and running surfaces.

The cam assembly looks like new after polishing and cleaning. Hard parts need abrasive cleaning with appropriate soda or glass bead blasting. The breaker plate can be re-plated if necessary, using a zinc electroplating system like the one available from Eastwood Company. Apply these restoration procedures if new parts are not available.

These crucial parts are now restored. Cost of NOS parts can be high, depending upon demand. By restoring the housing, breaker plate, and cam assembly to perform as new, this Corvette distributor remains authentic and ready for another four decades of service. OEM and NOS parts assure the quality that Delco-Remy built into these components.

Before disassembly, the height of the old bushing was measured and noted. This new bushing must match the height of the original. If undersize, bushings should be reamed carefully. Once reamed nearly to size, bushings should be finished and burnished to match the shaft diameter. A drill motor, an old driveshaft, and lapping compound work well for this task. Metal polish can create a polished, final finish. Thoroughly clean away any abrasive.

Use an arbor press and proper diameter bushing drivers to prevent peening edges. Apply an anti-galling lubricant when pressing parts together. Size and burnish the bushings to fit. To maintain bore alignment of these two bushings, use a long reamer or polishing shaft to size both bushings at the same time.

Bushing positioned properly and polished in alignment with the lower bushing, this distributor is ready for assembly. Cleaned in a parts washing cabinet, glass beaded and then washed again, the housing looks new. Iron is strong and durable. Later distributors shifted to aluminum housings, which require careful handling and mild abrasive cleaning.

Appropriate masking, primer, and paint will restore the housing to new appearance. Use a suitable engine-grade primer and paint. This Dupli-Color engine enamel covers well, has excellent adhesion on freshly scoured iron, and contains ceramic for heat resistance. Eastwood and others also offer products for these tasks.

This array of parts represents a true restoration. NOS centrifugal weights, a new driveshaft, drive gear, small parts, Echlin premium tune-up parts, a new primary wire and grommet, plus new shaft bushings create a like-new distributor! Points, condenser, rotor, and cap are routinely replaced.

Assembly is the reverse of disassembly. A felt pad and grease retainer help lubricate the breaker plate. The plate pivots on the upper housing bushing. Make sure that the retaining wave washer and nylon grease seal are properly in place. Bosch grease for breaker point rubbing blocks works very well in this grease cavity.

When rebuilding a distributor thoroughly, you will want to replace the vacuum advance unit. These calibrated vacuum canisters must match the factory rated pull. If you cannot find a canister match, based upon the distributor tag number, there are universal, adjustable canisters available from Mr. Gasket and others.

This is a strobe check of the vacuum and centrifugal advance mechanisms. Vacuum advance works at throttle tip-in and light throttle. The centrifugal advance weights and springs, located beneath the rotor, determine the rpm and degrees of total mechanical advance. Centrifugal advance responds solely to engine speed.

Wires must be clear of moving parts and able to move without chafing or wear over time. Keep wires well below the spinning rotor. Route wires away from metal edges. Lube the point rubbing block and oil wick with a grease like Bosch #5700 002 005. Apply grease as noted in the point set instructions.

Insert the tach drive gear's button if removed during service. Grease the tach drive gear and cavity. Use a new sealing washer at the base of the bronze coupling. Secure the coupling and spin the distributor shaft. The shaft drive gear uses a thrust washer(s) that must be installed between the gear and distributor housing base. Use a new pin to secure the gear.

Insert the tach drive gear's button if removed during service. Grease the tach drive gear and cavity. Use a new sealing washer at the base of the bronze coupling. Secure the coupling and spin the distributor shaft. The shaft drive gear uses a thrust washer(s) that must be installed between the gear and distributor housing base. Use a new pin to secure the gear.

This is the restored and run-ready #1111493 Delco-Remy distributor unit. The factory tag is on the collar of the housing, signifying the application (350 horsepower, 350 V-8). If you want a matching numbers restoration, this is it! Remove the cap to index the rotor position during installation in the engine.