Replacing distributor cap ford 8n

RWD

New User
I have a cracked distributor cap. It is a front mount distributor on a
1948 ford 8n. My access and visiblity are very much diminished by
a front loader. If I pull the distributor as has been suggested, and
redo points, condensor, cap and rotor, how do I re-set the timing?
The distributor doesn't rotate like a later model.
 
Actually, you have two problems.

Chances are very good that the weight of the loader has worn out the pivot pin allowing the axle to strike the distributor cap. Until you fix that, you will just keep replacing caps.

The pic is of an axle w/ a new king pin as high as it will go; as you can see, it has a good 1/2" before it will hit the cap.

The axle must move freely up & down. Full travel is about 9 1/2". Back & forth (front to back) should be negligible.

You need to remove the motor mount to get the pivot pin out.

The front flange on the pin is a teardrop shape. After you've removed the retaining bolt, use your drift on the side of the flange down low (narrow end of the teardrop)and your BFH to drive the flange toward the opposite side. This turns the pin in the hole and breaks the rust bond. Then whack it the other direction, apply some penetrating oil, and knock it out from the back. Breaking that rust bond before hammering it out makes the job much easier. Save the hold pin & make a hi-tech "pivot pin removal tool" as in the picture.




The front distributor was designed to come off of the tractor to replace/adjust the points. Remove the wire on the coil, remove the coil bail, remove the distributor cap & take the two bolts off. The base of the distributor has an offset tang & can only go back one way unless you really force it on. Look at how the points & condenser set in the distributor before you start pulling it down! Turn the tang & observe how the points open & close. If this is your first time doing it, draw a sketch!. Make sure you are using quality parts; the points should have a phenolic rubbing block & not the cheap white plastic crap. Use only Wells, Blue Streak or Echlin brand points. (* see below) Be careful not to ground the tip of the condenser wire to the body of the distributor when you replace the points. Do not break the little copper strip that goes to the points. (If you do, make another out of the old set of points) Also, make sure the condenser wire does not go through the same opening in the distributor that the coil pig tail does. The condenser wire goes the opening on the top right. Look at the old points; are they burned, pitted or mis-aligned? Check the point gap, .015 on all four lobes. Make sure the blade is at a perfect right angle to the points & you want to feel just the slightest bit of drag when you pull the blade through the points. Set the points on the highside of the cam. Make sure you have the star washers under the screws on the points. Dress the points by running a piece of card stock or brown paper bag through them. New points sometimes have an anti-corrosive dielectric coating on them & old points can corrode or pick up grease from a dirty feeler gauge or excessive cam lubricant. And, don’t forget to lube the rubbing block w/ cam lube; not Vaseline, not bearing grease, but cam lube. (** see below)

Now, set the timing. Get a meter or test light, a 21/64” drill bit & a metal straight edge. Put the distributor face down w/ the condenser on the left & the timing plate lock screw on the bottom. Look at the end of the shaft: it has a narrow side & a wide side. Make sure you can tell the difference. Now, place the drill bit in the bottom mounting hole. (this will be your reference point for measuring) . Next, place a straight edge on the wide side of the tang on shaft as shown in fig. FO83 in the I&T FO4 manual. Rotate the shaft CCW (as viewed from rotor side OR CW as viewed from back/tang side) until the straight edge is ¼" beyond the outside edge of the drill bit you stuck in the distributor mounting hole. At this distance, the distributor points should start to open. (get your meter/light out now & check) If not, loosen the timing plate lock screw and turn to advance or retard the timing. (move the plate down to advance timing, up to retard) Remember, each one of those little hash marks represents about 4* of timing. Keep adjusting until you get the proper ¼" setting. (if the plate won’t move, you might need to remove the big C clip to loosen it a bit) As you’re adjusting, eliminate backlash by turning the shaft backwards (CW as viewed from the front) and bring the shaft forwards (CCW as viewed from the front) to measure your setting. This ¼" setting will get you static timing at top dead center.

After you set the points & timing, do a continuity check before you put the distributor back on the tractor. Before you start, make sure your meter/light works (don't ask....)

With the distributor still off the tractor, follow these steps:

1. Coil off, cap off, points open. One probe on the brass screw & the other on both sides of the open points. On the side closest to the cam, you should have continuity. Not on the other side! If you do, you will also have continuity everywhere because the points are grounded.

2. Coil off, cap off, points open. One probe on the brass screw & the other anywhere on the body of the distributor. You should have no continuity! Now, rotate the tang on the distributor....as the points open & close, you have continuity (closed) and lose it when they open.

3. Put the coil on the distributor, cap off, points open. One probe on the lead on the top of the coil, the other on the cam side of the open points. You should have continuity!

4. Coil on, cap off, points open. One probe on the lead on the top of the coil, the other anywhere on the body of the distributor. You should have no continuity!

At this point, I just put the distributor, coil & cap all back on the tractor as a unit. The reason I do this is because it is real easy to get the cap or coil mis-aligned trying to put it back together one piece at a time & the result is something gets broken or you get a ‘no spark’ problem.

It's possible to put it back on wrong & break it. Look at the slot on the end of the cam shaft. What ever angle it happens to be, turn the distributor tang to match it. Make sure you can tell the wide side from the narrow side on both the cam & distributor! (close counts) Then place the distributor on the front of the engine, gently push it in place & slowly turn the distributor body until you feel the tang slip into the slot. Rotate the distributor body until the bolt holes line up. Then, hand tighten the two bolts until the distributor body is flush w/ the timing gear cover.

Post back w/ results & any other questions.



* NAPA part numbers:

· Points: FD-6769X

· Condenser: FD-71

· Rotor: FD-104

· Cap: FD-126

** Distributor cam lube: http://www.autoanything.com/fluids-manuals-63-771-1978/201A1960.aspx?kc=FFPMM
DSC02439.jpg

DSC03473.jpg

timing003.jpg

50 Tips
 
I broke the cap while replacing the altenator. Problem 1 solved. Can I just take off the cap, distributor still attached to engine, and replace the cap and rotor?? The cap seems well attached and I figure that using a srew driver to get the cap off will disturb the gasket above. The directions you gave for resetting the timing are Greek to me. If I have to remove the distributor from the block can I replace the cap, rotor and gasket and put the distributor back on.
tanks,
rwd
 
" The directions you gave for resetting the timing are Greek to me."

Sorry, but that's how it's done. What is it that you don't understand? Have you ever had the distributor off before?

"If I have to remove the distributor from the block can I replace the cap, rotor and gasket and put the distributor back on.

Ahhh, yea. That's what I said. If you're going to take it off, I'd replace the points and condenser as well.
50 Tips
 
What part of my reply to you over on Tool Talk did you not understand???

"Get the coil and it's gasket out of the way, then replace the distributor cap, then the gasket and coil. The "coiled spring thingy" and the little steel tab under the coil MUST not be bent/damaged and MUST make good connections with their respective connections in/on the distributor or it ain't gonna run!"
t other thread...
 
Never had the dist. off before. Your directions say to remove the cap before removing the dist. After removing the clamps can I pry the cap off? If I remove the dist. replace the gasket, cap and rotor will the rotor automatically be pointed in the right direction or can the dist, mount with the rotor turned180 degrees.
 
remove the coil.. get it out of the way, flip the caps off the cap.. get it out of the way.. remove 2 bolts.. snake the dizzy out.

reinstall as reverse process.

once you get the dixxy against the block, put in the 2 bolts loose, spin the rotor with a finger till the offset drive tang slips into the cam slot.. then bolt down

soundguy
 
Do like soundguy is saying. The dist can only be installed in the correct position. can not be install 180 degrees off. Look at the drive tang. It is off set so can only go one way. At least with out breaking something.
 
S.G., take a look at his original post... the way it looks to me he is simply trying to replace the cracked CAP and is frustrated by advice to remove the whole distributor!
 
then he could at least just remove the coil..

heck.. i get aggravated at having to fix stuff too.. but ya do what ya got to do.. :)

soundguy
 
Excuse me, because I don't mean to be a smart@ss w/ this comment......but are you actually reading the replies you're getting?

You asked " If I remove the dist. replace the gasket, cap and rotor will the rotor automatically be pointed in the right direction or can the dist, mount with the rotor turned180 degrees."

In my very first reply, I told you "The base of the distributor has an offset tang & can only go back one way unless you really force it on. "
 
Don't get fiesty. If I understood what an offset tang was it wouldn't sound like greek to me. Anyway I'll go on reading your replies as long as they are helpful.
tanks
 
Thanks, I wasn't sure if the offset tang (which I didn't understand)
governed the rotor shaft or the position of the dist. body.
rwd
 
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