Ignition Systems: Distributor: 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 module.

1. To disassemble, unclip and remove cap. Install a new cap if known to be faulty. Clean cap and high tension brush with a lint free cloth. Pull rotor arm from shaft. Install a new rotor arm if known to be faulty. Remove insulation cover (flash shield), secured by 3 screws. See Fig 1 . Install a new cover if known to be faulty.
2. Remove 2 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. Remove 2 screws and withdraw module. Remove gasket.
3. Remove 2 screws securing cast heatsink and remove heatsink. Use circlip pliers to remove circlip retaining reluctor on rotor shaft. Remove flat washer and then "O" ring recessed in top of reluctor.
4. Gently withdraw reluctor from shaft, taking care not to damage teeth.
   NOTE: Coupling ring installed beneath reluctor.
5. Remove 3 support pillars and cable grommet. Lift out pick-up and base plate assembly.
   NOTE: DO NOT disturb 2 barrel nuts securing pick-up module, otherwise air gap will need re-adjustment.
6. Fit a new pick-up and base plate assembly if module is known to be faulty, otherwise check pick-up winding resistance (2000-5000 ohm).
7. To reassemble, apply a spot of clean engine oil into rotor spindle before instating rotor arm. Apply Omnilube 2 (or equivalent) grease to auto advance mechanism, pick-up plate center bearing, pre tilt spring and its rubbing area (pick-up and base plate assembly), vacuum unit connecting peg (pick-up and base plate assembly), and connecting peg hole in vacuum unit connecting rod.
8. Fit pick-up and base plate assembly. Pick-up leads must be prevented from fouling rotating reluctor. Both leads should be located in plastic guide as illustrated. See Fig 2 . Check during reassembly.
9. Refit reluctor. Slide reluctor as far as it will go on rotor shaft, then rotate reluctor until it engages with coupling ring beneath pick-up base plate. Distributor shaft, coupling ring and reluctor are "keyed" and rotate together. Install "O" ring, flat washer and retaining circlip.
10. Adjust pick-up air gap. Air gap between pick-up limb and reluctor teeth must be set within specified limits, using a non-ferrous feeler gauge.
11. If adjustment is necessary, slacken 2 barrel nuts to set air gap. Air gap should be .008-.014" (.20-.35 mm). See Fig 3 .
    NOTE: When original pick-up and base plate assembly has been refitted air gap should be checked, and adjusted if necessary. When installing a new assembly, air gap will require adjusting to within specified limits.
12. Before installing module, apply MS4 Silicone grease or equivalent heat-conducting compound to amplifier module backplate, seating face on distributor body and both faces of heatsink casting.

Fig 1: Exploded View Of Distributor Assembly

Courtesy of LAND ROVER NORTH AMERICA, INC.

Fig 2: Identifying Pick-Up Leads Plastic Guide

Courtesy of LAND ROVER NORTH AMERICA, INC.

Fig 3: Adjusting Air Gap

Courtesy of LAND ROVER NORTH AMERICA, INC.