DIY Network

1938 Packard Ignition System: Servicing the Distributor From "Classic Car Restoration" episode DCR-403

The breaker-point ignition is responsible for advancing the charge to the sparkplugs, and does so via centrifugal energy as well as a vacuum advance mechanism.

In this episode of Classic Car Restoration, host Mark Lambert addresses the ignition system on the 1938 Packard Club Coupe. In this second segment of episode 403, he services the distributor, replacing the points and vacuum advance.

Materials used in this episode:

Standard automotive tools (socket-wrenches, screwdrivers, nut-drivers, etc.)
Bench vise
Hand-vacuum pump
Replacement points
Replacement vacuum-advance
Eye protection
Protective gloves

Note: This is a summary of steps included in the automotive restoration procedures shown in this episode of Classic Car Restoration. These are general guidelines for restoration procedures on this particular make and model of vehicle, and for the level of restoration selected for this project. There may be variations in procedures depending model, condition of vehicle, level of restoration undertaken and the types of replacement parts or upgrade kits selected. Always follow proper safety precautions, and read and follow manufacturer's guidelines, diagrams and safety notices that come with any replacement parts or kit that you select.

advertisement

	Figure A
	Figure B

Servicing the Distributor

• With the distributor removed from the Packard, it can be placed in a bench vise for stability while it is checked and serviced. The first step is to check the vacuum advance. The function of the vacuum advance is to cause the breaker plate to rotate a few degrees and advance the timing which is needed to operate at partial throttle.

• We checked the vacuum advance with a hand-held vacuum pump. Hook the pump to the vacuum-advance tube and operate the pump (figure A). Since the pump initiated no movement in the advance mechanism, the indication was that the advance was bad -- probably due to a diaphragm that had aged and deteriorated. The solution is to replace the mechanism with a new one containing a fresh diaphragm.

• Remove the vacuum advance line.

• Unscrew the cap and carefully remove (and retain) the washers inside.

• Using needle-nosed pliers, remove the spring (figure B).
  

• Unscrew and remove the vacuum-advance module's retaining screws and carefully lift the module away from the distributor body (figure C). Separate the module from its adapter. (The module adapter fits the vacuum advance unit to the body of the distributor.)

• Connect the adapter to the new module. Install the spring, washers and line-adapter.

• Use the vacuum pump once again to test the new vacuum-advance, just as you did with the old one. If the mechanism is operating properly, the pump will cause movement in the diaphragm and mechanism (figure D).

  Figure C

  Figure D

  
  

• Next, work can begin on servicing the points. Remove the rotor button, then use a screwdriver to assist in inspecting the points (figure E). Ours were visibly corroded.

• Carefully remove the fouled points. With the points removed, we could compare the old, corroded ones with the new ones to see the difference (figure F). The corroded and burned points will prevent an efficient coil-fire.

• You'll also need to remove and replace the mating side for the points. These are very small, and this is tedious work.

  Figure E

  Figure F

  
  

• Carefully install the new points. With the new inner point threaded in, tighten it down with a screwdriver (figure G). Reconnect the ground wire and condenser wire and secure them tightly.

• Use the tip of a screwdriver to check the clearance between the points and cam (figure H).

  Figure G

  Figure H

  
  

• Turn the adjusting screw and check the clearance again (figure I).

• Once the clearance begins to get very close, fit the lock-nut in place but leave it a little loose. Now you can make the final adjustments to the clearance using a feeler gauge according to Packard's recommended specs (figure J). The recommendation is for between 18/1000 and 22/1000. We aimed for 18 since the gap will get wider over time. Once the fit is correct, lock it in position, then double-check it and tighten the locking backup nut.

  Figure I

  Figure J

  
  

• Reinstall the vacuum advance (figure K)

• Reinstall the rotor button.

• Finally, all of the '30s era distributors come with a grease cup. Reload the cup with fresh grease and thread it back in place (figure L). As the cup is threaded down, it forces a small amount of grease through a hole to lubricate the shaft.

  Figure K

  Figure L

  
  

  Figure M

• Some Packard enthusiasts prefer to replace the breaker-point ignition with new solid-state electronic ignition (figure M). These are now available for 6-volt cars in positive ground. These are fairly simple to install and take the place of the points. We opted to stay with the original system for our project car.
  

RESOURCES :


Resources and Special Thanks for Classic Car Restoration 400 series


The Packard Club
Columbus, Ohio
(National & regional clubs, car shows & judging, magazine, resources, etc.)
The Cormorant magazine
The Packard Club
www.packardclub.org

Packards International Motor Car Club
(National owner's club, judging rules, magazine, newsletter and other resources)
Santa Ana, CA
Packardsinternational.com

Packards of Chicagoland
(Regional affiliate of The Packard Club)
Elmhurst, IL
Packards of Chicagoland

America's Packard Museum
Dayton, Ohio
www.americaspackardmuseum.org

The National Packard Museum
Warren, OH (the birthplace of the Packard)
www.warren.org

The Packard Motor Car Foundation
(Foundation for preserving the Packard marque) Restoring the Packard Proving Grounds and other Packard activities.
www.packardmotorfdn.org

Motorbooks International
www.motorbooks.com

Automobile Inspections LLC
(Nationwide automobile appraisal & inspection services, including classic cars)
Hartford, CT
www.automobileinspections.com

Classic Auto Appraisals (Evaluation of Classics, Street Rods, Antiques, Competition Cars, Exotics, Commercial Vehicles and Hand Crafted Vehicles).
www.autoappraisals.com

GUESTS :

Keller Wallace
Keller Wallace Street Rods
Volunteer Street Rod Association
Knoxville, TN