See Figures 1, 2 and 3
It is important to remember that for purposes of replacement, the breaker points and the condenser should be treated as a unit. One should never be replaced without replacing the other.
There are two ways to check the breaker point gap: with a feeler gauge or with a dwell meter. Both methods serve the purpose of adjusting the amount of time (in degrees of distributor rotation) that the points will remain open. If you adjust the points with a feeler gauge, you are setting the maximum distance which the points will open when the rubbing block, which is affixed to the point assembly, is on the highest point of a distributor cam lobe. When you perform the same point adjustment with a dwell meter, you are measuring the number of degrees (of distributor cam rotation) during which the points will remain closed before they start to open as a high point of the distributor cam approaches the rubbing block on the point assembly. Either/both method of point gap adjustment may be employed during a tune-up, but the dwell meter adjustment is the more precise and should be used last as the final adjustment of point gap.
A final rule governing the adjustment of point gap is that whenever point gap is adjusted, ignition timing must also be checked and adjusted accordingly.
REMOVAL & INSTALLATION
See Figures 4 through 17
- Disconnect the high-tension wire from the coil and unsnap the distributor cap retaining clips.
- Remove the distributor cap from the distributor with its wires still in place. Turn it so that you can examine the inside of the cap. Check carefully for cracks. Examine the metal strikers. If they are excessively worn or burned, or if the cap is at all cracked, it should be replaced. If you are replacing the distributor cap, leave the wires in place on the old cap until you have the new cap in hand, and ready to install. Transfer the wires one at a time, to avoid installing them on the wrong fittings. Position the distributor cap out of the way of the distributor.
- Remove the rotor from the distributor shaft by pulling it straight up. Examine its condition. If the rotor is cracked or the metallic tip is excessively burned, it should be replaced.
- Remove the metal point shield, if your car is so equipped.
- Place a screwdriver against the breaker points and pry them open. Examine the condition of the contact points. If they are excessively worn, burned, or pitted, they should be replaced.
- If the points are in good condition and not in need of replacement, proceed to the breaker point adjustment section which follows the breaker point replacement procedure.
- Disconnect the primary lead and the condenser wires from the breaker point assembly. On centrifugal advance distributors, remove the jumper strap also.
- Remove the breaker point assembly and condenser retaining screws. Lift the breaker point assembly and the condenser from the distributor.
- Lightly lubricate the distributor cam with heat-resistant lubricant.
- Place the new breaker point assembly and condenser in position within the distributor, and install but do not tighten the screws.
- On Loadomatic distributors (pre-1968 six-cylinder engines), position the ground wire under the breaker point assembly screw, and connect the primary and condenser wires to the breaker point assembly. On all V8 engines, except those equipped with a centrifugal advance distributor, place the ground wire under the breaker point assembly screw farthest from the breaker point contacts. On six-cylinder engines from 1968 to the present, this ground wire should be placed under the condenser retaining screw.
- If the two contact points of the breaker point assembly are not parallel, bend the stationary contact slightly to correct. Bend only the bracket portion of the assembly, do not damage the contact surface.
- Turn the engine until the rubbing block on the point assembly is resting on the high point of a distributor cam lobe. Using the proper thickness gauge for the point gap specifications of your car, adjust the point gap, and tighten the retaining screw.
- Check the gap with a feeler gauge, in order to make sure that it was not altered by the tightening of the retaining screws.
- Connect the primary and condenser wires to the breaker point assembly in the same order in which they were removed. If your distributor is equipped with the metal point shield, the wires should be positioned at right angles to each other, or at 180º to each other. The purpose of this placement is to avoid the possibility of wire terminals contacting the metal point shield, thus creating a short circuit and a resultant no-start situation.
- Install the metal point shield if your distributor is so equipped.
- Push the rotor onto the distributor shaft, after aligning the tab inside the rotor with the notch on the shaft. Make sure that the rotor is fully seated on the shaft.
- Align the tab inside the base of the distributor cap with the notch on the rim of the distributor body. Install the cap on the distributor, making certain that it is fully seated. Snap the distributor cap retaining clamps into place on either side of the cap.
- Install the coil high-tension wire at the coil.
- If you are checking your breaker point adjustment with a dwell meter, read carefully all instructions included with your dwell meter and connect the dwell meter accordingly.
- Start the engine.
- Observe the reading on the dwell meter. If the reading is within the specified range, stop the engine and disconnect the meter.
- If the reading is above the specified range (in number of degrees) the breaker point gap is too small. If the reading is below the specified range, the breaker point gap is too large. In either case, stop the engine. Remove the distributor cap, rotor, and point shield (if so equipped), and adjust the points accordingly. Reassemble the distributor, start the engine, and take another reading on the meter. Repeat the process if necessary.