8BA Distributor end play

elwood

Well-known member
Hey guys, I was wondering what a distributor shaft end play should be ?
Ive got .240 in this one, to much ?
Thanks
 
.240 would be way too much , i would think .050 would work.
.240 may not cause a problem but i would wonder how it got that way etc ????
Theres really no load on a 8ba unit as it doesnt drive anything but the point set and the rotor would push the play downward .......
I would shim it or take apart to see why the play is so large, bottom gears are a bear to remove .....
 
If you can move the shaft that much your points would jump off lobe.
Does it work? broken shaft maybe.
Any way its down pressure. Try it and see if it works.
 
On page 88 of the 1949-51 Mercury Overhaul Manual it says that the distributor shaft end play is .002 to .005 inches. If greater than .005 shaft has to be replaced.
 
I talked to elwood on the phone today his problem distributor is one of mine ( gasp).
He is sending it back for repairs , i will post the results when i fix it.........
Beats me as i am the gear guy at the shop, had to be one i did?????????
Hate it when this happens !
 
There are two different gears. One for the early truck type and then one for the shaft that has the pilot on the bottom end. Maybe a gear upside down? Beats me.
 
OEM is as 19Forty says, had the same problem with one of Bubbas dist. with a Pertronics it will make a knocking sound, just take the gear off and shim it really didn't want to ship back dist. still works great 3-4000 miles Laurie
 
On page 88 of the 1949-51 Mercury Overhaul Manual it says that the distributor shaft end play is .002 to .005 inches. If greater than .005 shaft has to be replaced.

That's what I set 'em at, 0.002-0.005, defiantly less than 0.007"
0.050" is way, way to much. Quarter inch! Good Lord, there be a problem!
How did it get that big without the rotor hitting stuff?
Martin.
 
Got it back today and "Houston we have a problem" had every bit of .250 or more . Seems as if the lower bushing had been pounded upward in the distributor case !!
Prior to machining we press the bushing upward so that we dont cut much of the bushing away. Then we machine the housing to allow proper location with cylinder head clamp on the head. The we machine the housing size to allow .025-.030 housing bushing to new drive gear clearance. This allows oil to lube the lower end and the rotor is spring loaded to cap for downward push etc..
After shipping over 900 like this it seems to work very well.

Somehow ????????? this one had pressed the bushing upward in the housing and we are blaming shipping etc. On our end we will ship in a different wrap from down on to help prevent this ever happening again. Pic shows box when returned etc , seems as if the shippers trow each box off the barn roof every time ????

On this one i installed an new bushing cut to size and ran on tester making sure its correct .....
Sorry Elwood , i added some Newport Oil for your trouble.............:eek:
 
Got it back today and "Houston we have a problem" had every bit of .250 or more . Seems as if the lower bushing had been pounded upward in the distributor case !!
Prior to machining we press the bushing upward so that we dont cut much of the bushing away. Then we machine the housing to allow proper location with cylinder head clamp on the head. The we machine the housing size to allow .025-.030 housing bushing to new drive gear clearance. This allows oil to lube the lower end and the rotor is spring loaded to cap for downward push etc..
After shipping over 900 like this it seems to work very well.

Somehow ????????? this one had pressed the bushing upward in the housing and we are blaming shipping etc. On our end we will ship in a different wrap from down on to help prevent this ever happening again. Pic shows box when returned etc , seems as if the shippers trow each box off the barn roof every time ????

On this one i installed an new bushing cut to size and ran on tester making sure its correct .....
Sorry Elwood , i added some Newport Oil for your trouble.............:eek:
Trying to get this straight in my feeble mind, is this a stock or a modified GM distributor?
 
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