Distributor shaft endplay

[PT81PlymouthPickup]

Anyone know what the spec is for distributor shaft end-play on our flathead 6's?

[Eneto-55]

Bushings wear?  Manual says to replace them if more than .008. (To be measured at the top of the distributor drive shaft.)

[PT81PlymouthPickup]

1 hour ago, Eneto-55 said:

Bushings wear?  Manual says to replace them if more than .008. (To be measured at the top of the distributor drive shaft.)

Thanks Eneto! Are you referring to side play or end play? I've installed a new shaft and bushings. It now measures with indicator .001 side play at top of distributor. Now I need to drill the new shaft for the retaining collar. depending on where I drill it, will determine the end play. I can't seem to find a spec. on that. To clarify, I'm referring to the clearance or movement in line with the shaft.

[desoto1939]

When you replaced the two bushing s upper and lower did you burnish the bushing for an exact size.  There is a factory miller tool that is used to drive in and out the two dizzy bushings.  You also should have a metal pin that has been peened over just below the base of the main body of the dizzy. So why are you redrilling another hole? Just use the same hole with a new pin and peen over the ends The miller tool is c-3041 and is currently listed on ebay for around $59.

 

Rich Hartung

desoto1939@aol.com

[Plymouthy Adams]

I agree Rich...the collar should go back in the same position...drill extra holes here will lead to weakening the the shaft....often these drilled holes cannot be 180 out due to a bit drift......if you drill to close to the original hole...this could lead to bit walking and misalignment.  IF you are having end play issues...first check for bushing fit for being "home" add or reduce spaces as needed...if no spacers and you do not align...again look at the home position of the bush...play, add shims...I would look to a light file of the collar before drilling a new hole...

Edited July 7, 2020 by Plymouthy Adams

[Eneto-55]

2 hours ago, PT81PlymouthPickup said:

Thanks Eneto! Are you referring to side play or end play? I've installed a new shaft and bushings. It now measures with indicator .001 side play at top of distributor. Now I need to drill the new shaft for the retaining collar. depending on where I drill it, will determine the end play. I can't seem to find a spec. on that. To clarify, I'm referring to the clearance or movement in line with the shaft.

The manual is not totally clear - I wondered myself which measurement they were indicating, but I'd say they are talking about "side play", or lash (if I have the correct term).  The holes you need to drill are in case the bushings do not have oiling holes, or if they do not line up.  I am including both sections from the manual I have (P15 thru P20 service guide):

 

DISASSEMBLY AND INSPECTION OF DISTRIBUTOR 

Remove the vacuum control unit before removing the breaker plate assembly. Inspect the bearing in the breaker plate assembly for binding, roughness or excessive looseness. Inspect the breaker points for burning or pitting. High resistance in the generating circuit due to loose connections or corrosion may have caused the points to oxidize. Loose condenser connections or high resistance within the condenser may be the cause of burned points. Remove the felt wick and the snap ring which holds the cam and stop plate to the drive shaft. Clamp the distributor in a vise. Do not tighten the vise excessively; otherwise, the bushing may become distorted. Check the distributor shaft bushings for wear. Attach a dial indicator to the distributor base and adjust the plunger of the indicator against the top of the drive shaft. Move the shaft "to and from" the indicator with just enough force to indicate clearance. See Figure 6. 

Too much pressure will cause the shaft to spring and show a false reading. If the clearance is more than .008 inch, replace the bushings. File off the end of the rivet and drive it out of the drive shaft collar at the lower end of the distributor base. Push the shaft up through the collar and base. Press the bushings from the distributor base. 

ASSEMBLY OF DISTRIBUTOR 

Before installing new distributor shaft bushings, they should be soaked in light engine oil for about 15 minutes. If there are oil holes in the bushings, be sure they are lined up with the oil holes in the distributor base, before pressing them into place. If there are no holes in the bushings. press them into the distributor base and drill with a 1/8 inch drill. It will be necessary to remove the oiler to drill the upper bushing. Ream the bushings to shaft size. Remove the burrs from inside the bushings and blow out all chips. 

Install the upper thrust washer on the distributor shaft and place the shaft into the base. Install cover washers and the retaining collar. Insert the rivet in the distributor shaft but do not peen it. Measure distributor shaft end play by pressing on the top of the shaft and placing a flat feeler gauge between the bottom of the base and lower thrust washer. If the end play is within specifications, peen over the ends of the rivet. If the end play exceeds .008 inch, replace the thrust washers. 

Lubricate the governor weights. See Figure 8. 

Place the cam and stop plate over the end of the shaft and the lugs on the governor weights. Install the spring lock ring and felt wick at the top of the drive shaft. Install the breaker plate assembly in the distributor body. Install the vacuum control unit. Adjust the breaker points and test the breaker arm spring tension. 

Hook a spring scale on the breaker point arm at the point end and pull at right angles to the point surfaces. Take a reading as the breaker points separate. The spring tension should be 17 to 20 ounces. Loosen the screw which holds the end of the breaker point spring and slide the end of the spring in or out as necessary. Tighten the screw and check the tension. 
 

[PT81PlymouthPickup]

1 hour ago, desoto1939 said:

When you replaced the two bushing s upper and lower did you burnish the bushing for an exact size.  There is a factory miller tool that is used to drive in and out the two dizzy bushings.  You also should have a metal pin that has been peened over just below the base of the main body of the dizzy. So why are you redrilling another hole? Just use the same hole with a new pin and peen over the ends The miller tool is c-3041 and is currently listed on ebay for around $59.

 

Rich Hartung

desoto1939@aol.com

Thanks for the reply Rich, I'm installing an NOS shaft. It does not have a hole.  I can set it up to drill  accurately in a milling machine, but to position correctly I need to know what the end play is supposed to be. I checked two old distributors. One measured .018 the other .025. That seems like too much to me?  I'm familiar with working with the peened pins, but I was wondering if a roll pin could be used? I'm guessing the peened pins are a lot less likely to come loose?

[PT81PlymouthPickup]

1 hour ago, Eneto-55 said:

4 hours ago, PT81PlymouthPickup said:

Thanks Eneto! Are you referring to side play or end play? I've installed a new shaft and bushings. It now measures with indicator .001 side play at top of distributor. Now I need to drill the new shaft for the retaining collar. depending on where I drill it, will determine the end play. I can't seem to find a spec. on that. To clarify, I'm referring to the clearance or movement in line with the shaft.

The manual is not totally clear - I wondered myself which measurement they were indicating, but I'd say they are talking about "side play", or lash (if I have the correct term).  The holes you need to drill are in case the bushings do not have oiling holes, or if they do not line up.  I am including both sections from the manual I have (P15 thru P20 service guide):

Thanks a bunch Eneto! This is just what I was hoping to find. It states more than .008" on either axis is too much. That tells me .001 or .002 should be just fine. I very much appreciate you taking the time to post that for me. ?