So Fix it

Breaker point distributors were standard equipment on most vehicles prior to the 1970s. The point distributor has a cam-type lobe that opens and closes the breaker points. When the points close, primary voltage is sent to a coil, and the coil sends high voltage to ignite the fuel charge via the spark plug. This sequence is timed for each cylinder as the engine rotates. The distributor cap must be removed to adjust the point gap on most distributors. GM trucks have a small door molded into the cap that provides access to adjust the points while the engine is running.

Instructions

Adjust the Points With a Feeler Gauge

1

Pull the keys from the ignition and pop the hood of the truck. Locate the distributor cap and follow the center ignition wire from the distributor cap to the coil and remove this wire. Most coils mount on top of the engine or the top side of the firewall.

2




Unsnap the clips or remove the screws that hold the distributor cap in place and lift it off the distributor.

3

Remove the rotor button from the top of the distributor shaft. Some rotors are attached with screws, and others just seat over the shaft into a groove to keep the rotor properly aligned.

4

Turn the distributor shaft by rotating the fan blade by hand until the high spot of the distributor lobe opens the contact points or is under the fiber bridge. Turning the fan may require that slight pressure be applied to the fan belt in the direction that the fan is turned.

5

Loosen, but do not remove, the screw that allows the breaker points to move in or away from the distributor shaft.

6

Place a .019-inch feeler gauge flat between the contact points and move the points in or out until the feeler gauge just fits between the contacts. Once adjusted, tighten the hold-down screw. Recheck the point gap, after the screw is tightened, to ensure that the feeler gauge retains the proper fit. If the gap is not right, repeat the adjustment.

7

Insert the keys into the ignition and turn the engine over while an assistant checks to see that the breaker points open and close properly as the distributor shaft rotates.

8

Install the rotor button on the distributor shaft. Look under the rotor button. Some rotors have a square and a round peg that must be inserted in their respective locations. Other rotors just slide into a groove.

9

Replace the distributor cap and coil wire.

Adjust Points With a Dwell Meter

10

Connect the positive lead of a dwell meter to the primary coil wire that comes out of the distributor. Ground the negative lead.

11

Crank the engine over when dwelling the points and observe the gauge reading.

12

Adjust the points contact gap, when dwelling the points, to change the dwell reading. Refer to a service manual for your trucks make, model and year to get the correct number for dwelling the points. Use the same method to adjust the points as in Section 1 but without the feeler gauge.

The venerable generator provided the electrical power for all types of vehicles during the early years of the automobile. The generator used a spinning armature to generate DC electrical power and in practice was both rugged and reliable. With the advent of more electrical accessories like power windows, the generator could not meet the additional demands and was replaced by the more powerful alternator. Many collector cars on the road today still use a generator, and from time to time a rebuild is required. Rebuilding a generator at home is both an easy and rewarding experience.

Instructions

1

Disconnect the battery ground cable from the battery terminal. Remove the wire leads from the generator, making note of which terminal they were attached. Squeeze the generator belt with your hand and loosen the pulley nut with an open end wrench. Squeezing the belt prevents the pulley from turning. Remove the pulley from the generator. Remove the generator hold down bolts and lift the generator off the car.

2

Remove the commutator end frame by first removing the through bolts. The through bolts are either fastened with a hex-head bolt or by a slotted screw. Tap the end frame with a rubber mallet to loosen it from the field frame. Remove the drive end frame and armature assembly from the field frame. The armature assembly is the part with all the copper windings around a central shaft and will slide out from the field frame.

3

Clean the commutator end frames, commutator, and field frame with a clean cloth. Do not use solvent of any kind on the generator parts. Inspect the end bearings for excessive wear or corrosion. Replace the end bearings if they appear pitted or worn.

4

Examine the commutator for high bars, high mica, pitted bars or excessive wear. Turn the commutator on a lathe if any of these conditions are present. Clean the commutator with a fine grade of sandpaper if it appears to be in good condition. Wipe off any sandpaper residue or dirt with a clean cloth.

5

Remove the brushes from the field frame and discard. Clean any corrosion off of the brush frames and install new brushes. Ensure the preformed angle of the brush matches the commutator contour. Ensure the brush frame springs are in good condition and maintain tension on the brush. Replace any springs that are worn or broken.

6

Test the armature for ground faults. Place one lead of the growler probe on the armature core and the other lead on the commutator bar. If the growler lamp lights up, the commutator is grounded and must be replaced.

7

Place the armature in the V-notch of the growler. Turn the growler on and touch the armature with a metal hack-saw blade. The hack-saw blade will become magnetically attracted to the armature and will vibrate if the armature is good. Rotate the armature and check each winding in the same way.

8

Test the field coil for open circuits. Place on lead of the growler probe on the field terminal and the other lead on the field coil lead to the armature terminal. If the lamp does not light then the field coils have an open circuit and must be replaced.

9

Test the armature terminal for ground faults. Place one probe of the growler to an armature terminal and place the other probe on the generator frame. If the lamp lights then the terminal insulation through the generator frame has broken down and must be replaced.

10

Test the brush holders for ground faults. Place one probe of the growler on the insulated brush holder and the other probe to the generator frame. If the growler lamp lights then the brush holder is grounded and the insulation must be replaced.

11

Solder any loose wires and replace any bad ground insulation as required.

12

Install the armature into the field frame. Install the end frame, being careful not to damage the brushes on the commutator. Install the drive end frame and install the through bolts. Install the drive pulley and fasten the pulley nut hand tight.

13

Install the generator onto the engine and install the hold down bolts hand tight. Place the generator belt over the engine pulley and generator pulley. Tighten the generator belt using a pry-bar wedged against the generator frame and engine. Tighten the hold down bolts while holding tension on the generator with the pry-bar. Squeeze the generator belt with your hand and tighten the pulley nut with an open end wrench.

14

Attach the wire leads to their original mounting studs on the generator. Connect the battery ground lead to the battery. Polarize the generator by momentarily contacting the "BAT" terminal of the voltage regulator to the "GEN" or "ARM" terminal using a jumper wire. Apply 8 to 10 drops of light oil to the bearing oil cups located on each end of the generator.