RACE 3B8859 - Caterpillar

1. Remove the magneto from the test bench. 2. Remove the four screws (1) from the magneto cover (2). Remove cover (2). 3. Remove two screws (3) from the top of the distribution board. Put a screwdriver between the heat sink section and the pulser coil housing. Pull the screwdriver to remove the heat sink and end cap section. It may be necessary to lightly hit the end cap section with a soft hammer to remove the sections. 4. On magnetos with serial numbers less than 8,000,000, remove the pulser coil wires from terminal block (A) and from terminals (B-5) and (B-7).On magnetos with serial numbers over 8,000,000, remove the pulser coil wires from terminal block (C) and from terminals (B-6), (B-7), (B-9) and (B-10). 5. Remove the four screws (4) from the plate (5), which is between the pulser rotor assembly and the power board. Remove the plate. 6. Remove nut (6) and the washer which fasten the pulser rotor to the shaft. Remove the pulser (7).
Use extra care when removing nut (6). Do not use the drive coupling to keep the pulser shaft from turning. Damage to the fiber gear may result. Put a large nut over a pick-up on the pulser coil. Turn the drive coupling until the pulser comes in contact with the nut. Remove nut (6).
7. Remove the two screws (8) from the center of the pulser coil (9). Remove two screws (8) from the lower edge of the pulser coil. Remove the pulser coil with the defect and install the new pulser coil. If the new pulser coil has fiberglass tubing over the wires, terminal block (A) is not used. 8. If the new pulser coil does not have the extra long wires with the fiberglass tubing over the wires, connect all the wires as shown in the wiring diagrams (A), (C) or (E). Assemble the magneto and do the FAILURE ANALYSIS again to be sure there is no other problem. 9. If the new pulser coil has the extra long wires with the fiberglass tubing, remove the black wire from terminal (B-10). Remove the white/red wire, the white/green wire and the white/yellow wire, from terminal blocks (B) and (C). Remove the wires that connect terminal block (A) to terminal block (C).10. Pull the wires from the pulser coil through the heat sink and end cap opening. When all of the wires are through the opening, the end of the fiberglass tubing will be just beyond the edge of the opening. Connect the wires to terminal block (C) and four wires to block (B) as shown in wiring diagrams (B), (D) or (F). Be sure all of the screws on terminal block (A) are tight so they will not fall into the unit when it is running. Do not remove the screws.11. Assemble the magneto and do the FAILURE ANALYSIS again to be sure there is no other problem.Chart A Chart B Chart C Chart D Chart E Voltage Checks Torque