Chevrolet Full-size Cars 1968-1978 Repair Guide

Distributor

Print

REMOVAL & INSTALLATION



Point-Type Ignition


Click image to see an enlarged view

Fig. Fig. 1 Exploded view of a common six-cylinder engine's point type distributor

  1. Disconnect the negative battery cable. Remove the distributor cap and position it out of the way.
  2.  
  3. Disconnect the primary coil wire and the vacuum advance hose.
  4.  
  5. Scribe a mark on the distributor body and the engine block showing their relationship. Mark the distributor housing to show the direction in which the rotor is pointing. Note the positioning of the vacuum advance unit.
  6.  
  7. Remove the hold-down bolt and clamp and remove the distributor.
  8.  
  9. To install the distributor with the engine undisturbed:
  10.  
    1. Reinsert the distributor into its opening, aligning the previously made marks on the housing and the engine block.
    2.  
    3. The rotor may have to be turned either way a slight amount to align the rotor-to-housing marks.
    4.  
    5. Install the retaining clamp and bolt. Install the distributor cap, primary wire or electrical connector, and the vacuum hose.
    6.  
    7. Start the engine and check the ignition timing.
    8.  

  11. To install the distributor with the engine disturbed:
  12.  
    1. Turn the engine to bring the No. 1 piston to the top of its compression stroke. This may be determined by inserting a rag into the No. 1 spark plug hole and slowly turning the engine over. When the timing mark on the crankshaft pulley aligns with the 0 on the timing scale and the rag is blown out by compression, the No. 1 piston is at top dead center (TDC).
    2.  


On Mark IV (big block) V8 engines there is a punch mark on the distributor drive gear which indicates the rotor position. Thus, the distributor may be installed with the cap in place. Align the punch mark 2 degrees clockwise from the No. 1 cap terminal, then rotate the distributor body 1 / 8 turn counterclockwise and push the distributor down into the block.

    1. Install the distributor to the engine block so that the vacuum advance unit points in the correct direction.
    2.  
    3. Turn the rotor so that it will point to the No. 1 terminal in the cap.
    4.  
    5. Install the distributor into the engine block. It may be necessary to turn the rotor a little in either direction in order to engage the gears.
    6.  
    7. Tap the starter a few times to ensure that the oil pump shaft is mated to the distributor shaft.
    8.  
    9. Bring the engine to No. 1 TDC again and check to see that the rotor is indeed pointing toward the No. 1 terminal of the cap.
    10.  
    11. After correct positioning is assured, turn the distributor housing so that the points are just opening. Tighten the retaining clamp.
    12.  
    13. Install the cap and primary wire. Check the ignition timing. Install the vacuum hose.
    14.  


High Energy Ignition (HEI) System


Click image to see an enlarged view

Fig. Fig. 2 Exploded view of an HEI distributor with integral coil



Click image to see an enlarged view

Fig. Fig. 3 Remove the distributor cap, then matchmark the rotor to the distributor body, and the engine



Click image to see an enlarged view

Fig. Fig. 4 Remove the distributor hold-down-note the white alignment mark on the engine



Click image to see an enlarged view

Fig. Fig. 5 Pull straight up on the distributor body to remove the distributor from the engine

  1. Disconnect the negative battery cable.
  2.  
  3. Tag and disconnect the feed and module terminal connectors from the distributor cap.
  4.  
  5. Disconnect the hose at the vacuum advance, if equipped.
  6.  
  7. Depress and release the 4 distributor cap-to-housing retainers (2 retainers on the non integral coil distributor) and lift off the cap assembly.
  8.  
  9. Using crayon or chalk, make locating marks on the rotor and module and on the distributor housing and engine for installation purposes.
  10.  
  11. Loosen and remove the distributor clamp bolt and clamp, and lift the distributor out of the engine. Noting the relative position of the rotor and module alignment marks, make a second mark on the rotor to align it with the mark on the module.
  12.  

UNDISTURBED ENGINE
  1. With a new O-ring on the distributor housing and the second mark on the rotor aligned with the mark on the module, install the distributor, taking care to align the mark on the housing with the one on the engine. It may be necessary to lift the distributor and turn the rotor slightly to align the gears and the oil pump driveshaft.
  2.  
  3. With the respective marks aligned, install the clamp and bolt finger-tight.
  4.  
  5. Install and secure the distributor cap.
  6.  
  7. Connect the feed and module connectors to the distributor or distributor cap.
  8.  
  9. Connect a timing light to the engine and plug the vacuum hose, if so equipped.
  10.  
  11. Connect the ground cable to the battery.
  12.  
  13. Start the engine and set the timing.
  14.  
  15. Turn the engine off and tighten the distributor clamp bolt. Disconnect the timing light and unplug and connect the hose to the vacuum advance, if so equipped.
  16.  

DISTURBED ENGINE
  1. Remove the No. 1 spark plug.
  2.  
  3. Place a finger over the No. 1 spark plug hole and rotate the engine by hand until the compression can be felt.
  4.  
  5. Align the timing mark on the crankshaft pulley with the 0 mark on the timing plate.
  6.  
  7. Align the distributor rotor near the No. 1 spark plug tower.
  8.  
  9. Install the distributor, the hold-down clamp, the bolt and the cap. It may be necessary to turn the rotor a little in either direction in order to engage the gears.
  10.  

With the distributor installed, make sure that the rotor is aligned with the No. 1 spark plug tower of the cap.

  1. Check the ignition timing.
  2.  

 
label.common.footer.alt.autozoneLogo