Re: Rebuilding a Distributor

Posted by Marco on May 10, 1998 at 12:21:33

In Reply to: Rebuilding a Distributor
posted by Roger Dean on May 10, 1998 at 08:55:48

Roger,
The only washer originally used on the distributor shaft was A-22331 fiber thrust washer (1/32" x 11/16"). I would suggest a few other things to do before installation
1. There should little perceptable play in the shaft bushings (Approximately .001"). Excessive play at the top will make the point gap erratic. To much at the bottom will allow the oil to drain out prematurely.
2. There should be no perceptable latteral movement of the breaker plate (upper plate). Any movement will allow the point gap to change when advancing and retarding the spark. If you don't have a plate that fits neatly at the center hole, you can place the plate on an anvil (or rear of your bench vise)being sure the rivets are off the edge, and lightly peen arround the parimeter of the hole with a blunt punch until the hole shrinks to a proper fit. Avoid going to fast as you may need to file back high spots.
3. Check the length of the wire on the lower plate (assuming you're going with the original design). The wire used with the stamped steel upper plate measured 3 1/2" total length. If the wire is the correct length it should provide years of trouble free service. If it is to long it will end up folding and breaking the insulation and shorting over time.
4. After assembly check and gap the points (I run mine at .020"). Check the gap on all four lobes. The gap should be identical. I've seen up to .006" variation with modern replacement parts. If you find any variation you can rotate the cam on the distributor shaft to determine whether the problem is the disributor shaft or cam. Some modern shafts are not concentric between upper and lower diameters.
5. Oil the distributor and turn the shaft by hand until you see oil work through both upper and lower bushings.
6. The distributor body, cap, and rotor should all fit snugly. any movement that allows any of these items to shift off center will affect performance.
7. Check the rotor to body contact gaps. I must confess I had never measured these until the discussion came up on this board a couple weeks ago. Mine seem to vary considerably with different parts. Until I borrow some NOS parts I won't know what the original spec was. My Fordor is .017-.018" and runs well.
If all these items check out your distributor will perform like new and will be better than any professionally rebuilt unit I have ever seen. Don't take anything for granted, check it all!
Good luck,
Marco

Follow Ups:
Re: Rebuilding a Distributor Bob Johnson May 11, 1998 at 17:11:01(2)
Re: Rebuilding a Distributor Joe May 12, 1998 at 07:49:49(0)
Re: Distributor shafts Marco May 11, 1998 at 18:27:31(0)
Re: Fibre washer on bottom Joe May 11, 1998 at 08:15:48(2)
Re: Fibre washer on bottom Marco May 11, 1998 at 12:02:27(1)
Re: Thrust washers Roger Dean May 11, 1998 at 16:46:34(0)

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