Distributor for 427-400

[Ray G.]

Hello folks, as a shade tree wrench (if I'm lucky) can someone tell me how to inspect,oil and grease my distributor. Original 19k mile car with TI ignition. I have sent off the amplifier to be restored and wonder if I could save some money by trying to "tune up" the distributor myself or should I send it out also?? Thanks,

[Dino L.]

Re: Distributor for 427-400

Try this..http://www.tispecialty.com/articles/article6.htm
Pay close attention to proper shimming to eliminate play, tachometer cross gear wear in housing, gummed up springs/weights, proper advance curve per the shop manual, if an original 19k car, it should be a clean and inspect....no special tools except a sun machine to verify advance curve.

[Jim T.]

Re: Distributor for 427-400

With only 19K on your car's distributor I recommend removing it and then noting how the dot is aligned with the rotor, remove the drive gear. Remove the tach drive gear, don't loose the small hardened washer that goes on the tach drive gear shaft. Remove the distributor shaft and then you can remove the seal at the top of the distributor shaft and you will see the crud in this cavity. www.tispeciality.com has a great how to rebuild a distributor on his web site. He has a recommendation for the type of lubricant in install in the cavity you clean. I do not know if new seals are available from GM now, but they were once. They came in a package with extras.
Greasing the tach gear on installation will contribute not having to replace the distributor shaft and tach gear drive later.
Clean the centrifical weight pins and weights and very lightly lubricate.

[Joe L.]

Re: Distributor for 427-400

With only 19K on your car's distributor I recommend removing it and then noting how the dot is aligned with the rotor, remove the drive gear. Remove the tach drive gear, don't loose the small hardened washer that goes on the tach drive gear shaft. Remove the distributor shaft and then you can remove the seal at the top of the distributor shaft and you will see the crud in this cavity. www.tispeciality.com has a great how to rebuild a distributor on his web site. He has a recommendation for the type of lubricant in install in the cavity you clean. I do not know if new seals are available from GM now, but they were once. They came in a package with extras.
Greasing the tach gear on installation will contribute not having to replace the distributor shaft and tach gear drive later.
Clean the centrifical weight pins and weights and very lightly lubricate.

Jim-------


The felt seal and plastic retaining washer are no longer available from GM. However, I think they are available in the aftermarket.

[Duke W.]

Re: Distributor for 427-400

The plastic "seal" from NAPA is just a flat nylon washer rather than a "cupped" seal as original, but both the felt washer and original plastic seal can be carefully removed and reused.

Overhauling a distributor is easy as long as the shaft bushings are okay. The procedure is in the 1963 Corvette Shop manual and later CSMs. There is little difference between single point and TI.

Use a full synthetic NGLI #2 grease like Mobil 1 in the upper bushing grease well. DO NOT use any "lubricant" on the centrifugal mechanism. Just clean and wipe with WD-40.

Upon removal check shaft side play. It should be barely perceptible, and if so the bushings are okay. If not, the bushings should be replaced and honed by a machine shop with experience at that procedure. Also check end play before disassembly to determine what additional shims are required.

Upon assembly shim to achieve .002-.007" end play and be sure the dimple on the gear is pointing the same direction as the rotor tip. Get a Mr. Gasket 928G spring kit and use the lightest springs which should bring in the full 30 degrees centrifugal at 3000-3500. If the VAC needs replacement use a B20.

There are numerous threads in the archives about distributor overhaul and setting up the spark advance map.

Duke