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post #1 of (permalink) Old 06-14-2000, 07:52 PM Thread Starter
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Installing Distributor

Just got a new Distributor today. I have never installed one before so I can use all the help that I can get.
Thanks for your help,


77 CJ-7/232
86 cherokee
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post #2 of (permalink) Old 06-15-2000, 11:33 AM
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Re: Installing Distributor

You will need a few things that most guys would not think of ....

1. A bottle of 'White Out' correction fluid, or white chalk.
2. A wooden dowel rod of about 1/4" diameter, and about 12" to 18" long.
3. A pointed tip magic marker.
4. A socket that fits your crankshaft center bolt and a ratchet.
5. A socket that fits your spark plugs.
6. A wrench that fits your distributor tie down clamp.

Now, what to do...

1. Locate the #1 Plug wire on your engine.
If it's a Inline 6 cylinder or Inline 4 cylinder, it will be the front cylinder.
If it's a V-6 or V-8, stand to the side of the engine, and see which head it further forward.
That will be #1.

2. Locate the #1 plug wire tower on the distributor cap.
Mark the location of the plug wire tower on the distributor base. Make a scratch, or use the magic marker.

3. Make detailed drawings where each plug wire goes from the cap to the head(s)...
This is so you can get the plug wires back on correctly.

4. Take the distributor cap off. You DO NOT have to remove the wires from the cap.
Just flip the cap out of the way.

5. Disconnect the coil wire.

6. Turn the engine over ('bump' it with the starter) until the metal rotor nose points at the mark you made on the distributor under the #1 plug wire tower.
Make a 'White Out' mark on the metal nose of the rotor. A small white stripe is fine.

7. Clean off the timing marks on your front cover, and clean off the timing mark on your balancer.
(If you don't know what these are, or where they are, refer to a good service manual)
Use the White Out or chalk to mark the '0' (zero) timing mark, and the mark on the balancer.

8. Remove the #1 spark plug.
Stick your finger OVER the hole, (Not IN the hole), or use a cork lightly pressed into the hole.

9. Crank the engine over, two revolutions at a time.
You will begin to know the compression stroke when you feel it. It will blow your finger (or cork) off of the hole.
You are wanting to catch the engine on the compression stroke.
The compression stroke only comes up once every two turns of the crankshaft.

10. If the compression stroke comes just before the rotor nose points at your mark, you are ready for the next step.

If the rotor is pointed away from your mark on the distributor housing when the compression stroke comes, your current distributor is in 180 degrees out. (Very common)
If it is 180 degrees out, See below.
Assuming you found compression stroke, and the distributor nose pointed at the #1 mark, you are ready for the next step.

11. Turn the engine over until the rotor nose is just about an inch from reaching the mark you made on the housing.
Get a ratchet and socket that fits the crankshaft bolt, and turn the engine over by hand.
Stick the wooden rod in the cylinder until you contact the top of the piston.
Turn the engine over until your timing marks on the front cover and balancer align.
Then go a little past...
The idea is to feel with the wooden rod to see if the piston is all the way at the top (Top Dead Center) when the marks line up...

12. If the wooden rod says the piston is at the top, and the marks line up, and your rotor nose is pointing roughly at the mark you made on the housing, then you just verified your;
A. Current distributor is in correctly.
B. The harmonic balancer has not slipped the outside ring.
C. Your engine has not be rebuilt with the wrong timing cover or balancer.

(If the marks do not align at TDC, or the rotor nose is wrong, there is a problem, see below.)

If you make it this far, pat yourself on the back.
I know a lot of guys at the race track that can't get this far...

13. Now, with all the marks aligned, disconnect any wiring, and unbolt your old distributor and work it out of the hole. They can be really stubborn sometimes, but resist the urge to get a bigger hammer to get it out.
Working them back and forth sometimes helps, and turning the rotor also helps sometimes... But they can be a real b*tch...

NOTE, Compare your old and new distributors closely, especially where they seat on the engine, the timing gear, and oil pump drive.
They have to be identical from the shoulder where they meet the engine to the end of the drive shaft.
If you have any differences, or any questions if one is different, DO NOT PROCEED, consult a professional.

14. Hold your new distributor up so you can put the distributor cap on it.
Mark the housing under the #1 plug wire tower like you did the old one...

15. Take the distributor away from the distributor cap, and put the rotor on it.
Turn the rotor to point at the #1 mark you just made.

16. Put the distributor gasket on your new distributor. You can use a little vaseline to hold it in place while you insert the distributor.
You can also clean off the engine where the distributor goes, and use a little vaseline or engine oil to hold it there.
The point is, don't forget the gasket!!

17. Look at your distributor from the top, and make a smaller mark about 1/16 to 1/8 of a turn COUNTER CLOCK WISE from your #1 mark.
The distributor gear is spiral cut, and the rotor will turn as the distributor is being inserted. (sort of 'screws' in)
If your distributor normally turns clockwise, you have to turn it counter clockwise to compensate to get your rotor position to come out correctly.

18. 'Clock' your distributor so the vacuum advance is pointed in the correct direction.
Consult your repair manual for the correct 'clocking' position of your distributor.
Follow the directions of the manual, and don't go by where the old distributor was pointed.

19. Hold the distributor so the 'Clocking' is correct, turn the rotor so it's pointing at your second mark, and insert in into the engine.
Work it down as far as it will go.

Distributors often stop 1/4" to 1/2" above the engine.
This is normal. The oil pump drive is misaligned, and holding the distributor up so it will not seat.
If this happens to you, Hold slight down pressure on the distributor, and turn the engine over by hand TWO TIMES, and bring the timing marks back to 'Zero' on the balancer.
The distributor should have dropped into place as the oil pump drive lined up.
If it didn't, turn the engine over TWO more times, pushing down on the distributor.
If that doesn't do it, there is another problem...
ALWAYS TWO TIMES. If you only do it once, you will be 180 degrees out.

20. With the balancer and timing marks aligned, the rotor should be pointing at your #1 plug wire tower mark, Plus or Minus about a 1/4" total.
If it's not, pull the distributor and try again, correcting your counter clockwise rotation to compensate.
It is normal to have to try it two or three times by beginners, so don't get discouraged.
Don't be tempted to just rotate the distributor to align the marks, as this will set the 'Clocking' of the distributor out.

21. Once the distributor is in place, and the rotor is pointing in the correct direction, and the timing marks on the cover and balancer align, you may install the distributor tie down.
Only clamp the distributor down enough it hold it in place.
You should still be able to turn it by hand with out too much trouble.
(You will tighten the distributor down securely after you get the timing set.)

22. Put your finger (or cork) back in the #1 Spark plug hole, and crank the engine.
You are looking to see if the compression stroke happens right before your rotor points at the #1 mark on the distributor housing.
If it does, you are ready for the next step.
If it doesn't, See below.

23. With everything aligned and verified, you are ready to install the distributor cap and #1 spark plug, connect the coil wire and the #1 spark plug wire.
Don't forget to install any distributor wiring.

24. Connect your timing light, and get ready to time the engine.
Have someone try to start the engine, While someone watches and corrects the timing.
It should start fairly easily.
If it's a breaker points ignition, set the dwell first before trying to set the timing.
If the rotor turns clockwise, (most do) turn the distributor clockwise to retard the timing.
Turn the distributor counter clockwise to advance the timing.
Reverse these directions for a counterclockwise rotating rotor.

25. Once the timing (and dwell, if needed) is set correctly, tighten the distributor hold down securely.

26. Pour six beers directly into your stomach, 'cause you are done!
If you run into trouble...

Checking for top dead center right at the end of the compression stroke is what you want to do.
Find compression, then insert the stick in the cylinder. Turn the engine over by hand to find Top Dead Center (TDC).
If the distributor doesn't agree, (usually pointing directly away from the #1 mark) but the timing marks agree and the compression stroke agrees, the distributor is 180 degrees out.
Pull the distributor out, and install your new one pointing at #1.

If you find TDC at the end of the compression stroke, and the balancer mark is somewhere other than at Zero, the outer ring of the balancer is slipped, or someone has installed an offset key, or it has the wrong timing cover or balancer.

Remember, TDC of #1 after compression stroke, and you can not mess this up.
Find compression, then find TDC, then install the distributor with rotor pointing at #1.

I recommend correcting any problems you find along the way, but this will keep you up and running while you are chasing parts.
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post #3 of (permalink) Old 06-15-2000, 12:06 PM
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Re: Installing Distributor

Great summary!
It's exrememly well organized and written.
I hope you are saving this one for inclusion into a forth coming web site.
I'm an old (racing) hand at this but I've printed it out as a check list because I'm getting ready to install my new MPI distributor.
Did you forget to mention lubricating the new dist gear?
Or is it unnessesary?

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post #4 of (permalink) Old 06-15-2000, 12:12 PM
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Re: Installing Distributor

Yup, I forgot...
A little engine oil or vaseline will do usually.

Assembly lube would be perfect, but most people don't have it on the shelf.

He said he was a beginner, so I tried to include everything with out using abbreviations or slang.
I saved it as a word document, so I could include it on a disk or web site...

Thanks for the kind words.

"I Have The Body Of A God... Buddha"
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post #5 of (permalink) Old 06-15-2000, 08:45 PM Thread Starter
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Re: Installing Distributor

TeamRush, Thank you for all of the info that you gave me, looks like it will be an all nighter for this ( I'm slow on this stuff ). I am doing the TR upgrade and I had to get a new distributor caus I have the crappy one ( I don't remember the name of it ). Thanks again, I will let you know if I get it right.


77 CJ-7/232
86 cherokee
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post #6 of (permalink) Old 06-16-2000, 02:25 AM
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Re: Installing Distributor

you must be applauded for such a well written reply.i am copying it as i type.well done

post #7 of (permalink) Old 06-16-2000, 09:12 AM
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Re: Installing Distributor

Thanks for the great post. I printed it and have it in a file for long-term reference.
I recently purchased a 1972 CJ5 that I am slowly going through, and nothing has been done correctly that I have torn into so far. How can people not take proper care of these great vehicles? ARRGH! So I expect the distributor will be no different. I will use this check list to make sure it is right, and fix it if it isn't.
Thanks again for a great post.
Happy Jeeping! George

'72 CJ5 V8 304 3Spd...pretty much stock
post #8 of (permalink) Old 06-16-2000, 10:05 AM
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Re: Installing Distributor

If you are using the Motorcraft distributor and DuraSpark ignition module (78 to 90, all V-8 and 258 I-6) in the older models, you will need a wiring diagram.
Up to and including '73, they used breaker points, '74 to '77, they used the Prestolite electronic ignition.
In both cases, the appropriate I-6 or V-8 distributor will drop in where the old points or Prestolite one came out.

In the case of switching distributors, you are going to have to strip off the wires and distributor cap.
Make careful notes of where the wires go. Consult your manual also.

If you are removing a breaker points or Prestolite distributor, and replacing it with a Motorcraft distributor and DuraSpark module, the attached diagram may help you with the new wiring you will need to install.

"I Have The Body Of A God... Buddha"
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post #9 of (permalink) Old 06-16-2000, 08:27 PM Thread Starter
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Re: Installing Distributor

TeamRush I want to thank you again for the info on the distributor install. My jeep runs better then it ever has in a long time. I am the second owner of the, CJ-7 ( My grandpa was the first ) it just pased 160 thousand miles two weaks ago. The jeep is all original except the radiator that I replaced three weaks ago and it is still running strong today. My grandfarther wanted me to say thanks again for the help and info that you gave us.

BTW- The wires that come out of the Prestolite distributor are both black, does it matter witch wires they go to or can they be reversed, and the wires that go to the distributor from the module are blue and white. Hope you understand this because i'm confused.


77 CJ-7/232
86 cherokee
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post #10 of (permalink) Old 06-17-2000, 07:20 PM
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Re: Installing Distributor

Don't ask me, I don't do Prestolite at all.
I did a little trying with them last year just to find out there was no helping them.
They failed so miserably on all counts I just trashed the ones we had here and never looked back.

Here is the way to tell polarity on any of the factory style hall effect triggers...
Hook them up one way.
Start the engine. Check the timing. Make a note of where the timing is around 800 RPM.
Kill the engine.
Switch the wires around (Reverse the polarity).
Start the engine. Check the timing. Make a note of where the timing is around 800 RPM.

Which ever way produces the least timing, (Most retarded) is the correct polarity.

(There goes another one of those old racing secrets...)

Every Prestolite that comes in here gets scrapped in favor of the Motorcraft/ DuraSpark ignition.
It's far superior, cheap, parts for it everywhere, and really upgradable.

If you switched to a Motorcraft distributor, you are only about $30 away from having a complete Motorcraft ignition. You need a module and a coil resistor wire.
(I'd spring for another $15 to $45 for the TFI coil and make it really usable...)
Jeep used them stock for about 12 years, with great success.

Look a post or two up to find the wiring diagram for the Motorcraft/ DuraSpark wiring diagram you need.

"I Have The Body Of A God... Buddha"
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