Posted by Marco on April 21, 1998 at 10:20:09
In Reply to: distributor shaft
posted by John Winchester on April 19, 1998 at 17:17:06
When everything was new the backlash measured approximately .070 at the tip of the rotor. With a typically worn (but not abused) camshaft and drive drive gear, the backlash is often closer to 3/16". It will run well under these conditions if timed well as Henry described.
When rebuilding or replacing the distributor be sure the upper plate with the points has NO lateral movement. Many "rebuilt" distributors I've seen have several thousanths lateral movement which allows the point gap to change an equal amount in use. There are ways to easily shrink the center hole in the plate if necessary.
In replacing the distributor shaft, if you are fortunate as Cecil has been, a one piece shaft will work great. However, in most cases the alignment is less than perfect and the one piece shaft will cause premature wear on the bushings. You can usually spot a one piece shaft on an idling engine from the wobbling motion of the distributor body! The original two piece shaft used by Ford provided somewhat of a universal joint link that will provide no additional backlash until many years of use.