Overhaul

WARNING: The amplifier module is a sealed unit containing Beryllia. This substance is extremely dangerous if handled. Do not attempt to open or crush the module.

DISASSEMBLY
1. Unclip and remove the cap.
2. Renew the cap if known to be faulty.
3. Clean the cap and HT brush with a nap free cloth.
4. Pull rotor arm from keyed shaft.
5. Renew rotor arm if known to be faulty.
6. Remove cover, secured by three screws.
7. Renew cover if known to be faulty.
8. Remove two screws from vacuum unit securing bracket, disengage vacuum unit connecting rod from pick-up base plate connecting peg, and withdraw vacuum unit from distributor body.
9. Remove two screws and withdraw the module.
10. Remove the gasket.
11. Remove two screws securing the cast heatsink and remove the heatsink.
12. Use circlip pliers to remove the circlip retaining the reluctor on rotor shaft.
13. Remove the flat washer and then the O-ring recessed in the top of the reluctor.
14. Gently withdraw the reluctor from the shaft, taking care not to damage the teeth.

NOTE: Coupling ring fitted beneath reluctor.

15. Remove three support pillars and cable grommet. Lift out the pick-up and base plate assembly.

NOTE: Do not disturb the two barrel nuts securing the pick-up module, otherwise the air gap will need re-adjustment.

16. Renew pick-up and base plate assembly if module is known to be faulty, otherwise check pick-up winding resistance (2k-5k ohm).

RE-ASSEMBLY
1. This is mainly a reversal of the dismantling procedure, noting the following points:

Apply Three drops of clean engine oil to felt pad reservoir in rotor shaft.
Apply Chevron SR1 (or equivalent) grease to:

a. Auto advance mechanism.
b. Pick-up plate center bearing.
c. Pre tilt spring and its rubbing area (pick-up and base plate assy).
d. Vacuum unit connecting peg (pick-up and base plate assy) and
e. The connecting peg hole in vacuum unit connecting rod.

Pick-up And Base Plate:

2. Pick-up leads must be prevented from fouling the rotating reluctor. Both leads should be located in plastic carrier as illustrated. Check during re-assembly.
3. Slide reluctor as far as it will go on rotor shaft, then rotate reluctor until it engages with the coupling ring beneath the pick-up base plate. The distributor shaft, coupling ring and reluctor are keyed and rotate together. Fit the O-ring, flat washer and retaining circlip.

Pick-up Gap Adjustment:

4. The air gap between the pick-up limb and reluctor teeth must be set within the specified limits, using a non-ferrous feeler gauge.
5. If adjustment is necessary, slacken the two barrel nuts to set the air gap.

NOTE:
- When the original pick-up and base plate assembly has been refitted, the air gap should be checked, and adjusted if necessary.

- When renewing the assembly the air gap will require adjusting to within the specified limits.

6. Before fitting the module, apply MS4 Silicone grease or equivalent heat conducting compound to the amplifier module backplate, the seating face on distributor body, and both faces of the heatsink casting.