distributer end play and rough idle

[pozest80hd]

Hi everyone'
finally got my 57 Fleetwood running and she will not idle smoothly no matter what I do. I pulled the distributer today and it has .125 slop up and down which seems excessive. I have searched but can not find a end play spec. does anyone know if my .125 is excessive and would it cause an erratic idle. I also noted when the car was running viewing through the distributer cap window that the point plate was rising and falling as it was turning. Let me know what you all think and as always thanks for the knowledge.

[Cape Cod Fleetwood]

End the misery.... Pertronix

[V63]

I doubt that is your issue.
There was a lot of up and down play with those. Only If you decide on pertronix that is an obstacle they all need to address. Otherwise it's the way they were.

I might start with the engine basics and verify compression and also vacuum. Isolate to only the engine vacuum ( temporarily eliminate wiper circuit) verify vacuum advance circuit. 

With dist out verify points and grounds.

[The Tassie Devil(le)]

As the engine is running, the angle of the Cam Drive Gear will always hold the distributor shaft in one direction, so some slop or play in this area will not matter.   This pressure holds the shaft against the thrust surface.

Bruce.

[James Landi]

"I might start with the engine basics and verify compression and also vacuum. Isolate to only the engine vacuum ( temporarily eliminate wiper circuit) verify vacuum advance circuit."

I'd start with the above suggestion, but in this order of priority, as follows:

"Isolate the engine vacuum"---if there are leaks (and you can almost count of them), the problem might be easily diagnosed by simply disconnecting all vacuum lines and plugging the intake manifold vacuum port, start the engine, and see if it runs better.

If you don't have one, purchase a vacuum gauge and read the instruction manual with care.  A vacuum gauge does diagnose most engine rough running issues without having you tear into engine components.
 
"...verify vacuum advance" --- largely "overlooked" by many folks, the vacuum advance TUNES the engine with your demand for power.  If the advance is ruptured (and they do!) you'll have a de tuned timing effect as well as a vacuum leak.   Hope this helps, James

[pozest80hd]

could anyone tell me the proper procedure for installing distributer want to make sure that I am doing that correct. (also when I set to tdc and pop distributer cap rotor is pointed in between 1 and 8 at firewall.) I have been putting number one piston at tdc and aligning balancer mark to c. then facing rotor cap spinning contact point  toward the number 1 of distributer cap which faces firewall. (seems against facing contact point of rotor at #1 spark plug and installing)
thanks again. I will also try a vacuum test (tested compression already have 1 at 115 rest are 130-155.

[fishnjim]

Not easy to tell from the described, but it's only a bushing system so won't be tight.  The gear and the clamp hold it down, so possibly the gear or cam gear is worn and sloppy. 
If it's not eating up the inside of the cap, it's probably not an issue.   You used to be able to pull them and send to the shop with a distributor machine, but those are non-existent, and only a few machines remain.  There's one or two on the internet but have no idea if any good.
You kinda have to find the right groove so when it drops down, the rotor is in the right position, may take a try or two.   Make sure it's TDC compression and not just TDC or you'll be 180 out.  But since it starts, probably OK.
There's too many things that can affect how it idles to list here and without how rough it is running? - guess  Vacuum is the first go to.  Air leaks and it won't ever smooth out.  Since it's not moving you can just block off the non-essentials.
One should always check all this stuff out before start up an resting motor.  Otherwise you get into the position you're now in, don't know what's wrong.
Had it all been checked out, you'd know and probably run good.

[TJ Hopland]

Is the dwell reading steady?  It should be even as you rev the engine.  If its jumping around that is a sign of worn bushings letting the shaft and thus the points cam move around which changes the dwell time which changes the timing and charterer of the spark.

[pozest80hd]

wanted to thank all replies. All comments were valid. I guess I am the type of guy who is ripping the motor down before doing what you all are saying. I will get the engine back to running (almost pulled the head) and start from the beginning, vacuum and go through the further steps from there. Also the comment about dwell reading steady will help pinpoint distributer accuracy. thanks again for all your help.

[The Tassie Devil(le)]

When pulling a distributor, you will notice that the rotor turns slightly as the unit is puller straight up and out.

This is caused by the angle of the distributor drive gear on the Camshaft.   So, when reinstalling it, one must slightly rotate the distributor shaft the same amount, so that when it drops back in, the gears will mesh.

The major problem is that if pulling the distributor out too fast, there will be a slight pressure created in the oil pump gearing, causing the gears to not stay in the "pulled-out" position, making reinstallation harder.   In a lot of cases, it might be necessary to insert a tool to preposition the oil pump drive shaft in order for the drive and bottom of the Distributor to properly mesh.

Bruce.

[James Landi]

TJ's comment about a worn bushing on the stator plate took me back 30 years ago when I couldn't get the damn engine from stumbling erradically.  I'd set the points, start the engine... it would run fine for a few minutes, begin to stumble, I'd check the dwell, it was off, adjust, same thing. DUH- the entire stator plate could be moved a fraction by simply pushing on it from side to side--- that bushing was simply worn from the vacuum advance doing its job.  A much more likely problem with distributors that are many decades old!   James

[Chopper1942]

When I rebuild a distrbutor. I always install a shim to eliminate excessive play between the gear and housing. I usually set it up with 0.040"-0.050" of clearance.  You need some play to insure that the upper dist bushing gets lube.

[pozest80hd]

Thanks again for the extra info on distributers. comment on the entire stator plate could be moved a fraction by simply pushing on it from side to side- I definitely am going to go through the distributer just for the fact that it moves from top of gear to d body .125 up and down is something I agree should be shimmed out to the smaller tolerances mentioned. anyway since I had already pulled the valve cover I started pulling the lifters and pushrods to give them a go through. After that I will put her back to running and start all things mentioned from all of you. thanks again for all the help and ideas. 

[bcroe]

Certainly check for excess wear.  Egg shaped lower
bearing.  I would do the overall test, muscle the
crank around to a timing mark, then back it up to
see how many crank degrees turn before the rotor
starts to follow it.  6 degrees means you are
headed for failure.

I sometimes move the timing spark pickup ahead
4 cylinders in the firing order (1 crank revolution),
the timing should read exactly the same. 
Bruce Roe

[Chopper1942]

Definately get a shim and install. Will help keep the fiming from fluctuating.