There are no specs I am aware of. I recall about 1 mm.
With the 3 small Allen screws loose, there is a little play which allows you to center the star wheel by eye.

I have never used a puller because it's too akward.

The star wheel can be tight on the shaft.
I use penetrating oil (Not WD-40) for a few hours.
Then, clamp the distributor securely between pieces of wood in a vice.
Place 2 big flat screwdrivers across from each under the THICK part of the star wheel and resting on the walls of the housing.
Now, take a deep breath and push down hard on the screwdrivers with sudden force.
It's the leverage that does the trick.
The fulcrum-point is the housing wall with the shorter leg towards the star wheel and the much longer leg towards the handles. That multiplies the force applied under the star wheel.
As it moves up on the shaft, watch for the very small dowel.
Penetrating oil, big screwdrivers and leverage. :)

The distributor has to come appart. Otherwise, you cannot clean and oil the very important advance mechanism, especially the center-bearing. It has to be completely smooth.
Try again and let us know if the above worked for you.

Thanks greatly Gunter, I'm going back in....;)

Mike...:cool:

This is something I would advise everyone to do. It is so easy took me about 1 hour. Now my dizzy was not exactly what I would have called dirty the spindle moved freely though felt a bit gummy. I opened it up as per Gunters instructions cleaned oiled re-assembled and installed. Must say I noticed a difference immediately. Re-set my igniton timing to 25deg BTDC @ 4,000 rpm. The car is running a lot better, now roll on Thusday to get her to the Bosch man to get my CIS tweaked....

Vacuum advance connection
 

I am a little confused - which vacuum connection is correct for the distributor advance?

'78 SC

I have a vacuum line coming from the front of the TB (front of car) and another coming from the rear of the TB (rear of car). I thought the front line was vacuum advance for the distributor and rear line was for a device in the air injection system. (which I have removed and need to plug)
Somebody please set me straight!

For a '78, you should have vac advance only, no retard.
Is the Bosch number on your distributor 0 237 306 001 ?

Vac advance goes in the rear of the TB (front of car)
Where exactly did the vac line from the front of the TB go to?
Which devise?
Picture would help.
There is no air injection system in an SC. Ooops, '78 has the pump.

Distributor vacuum line
 

My distributor number is 0237 306 001 PGFU 6.
So I am correct - the vacuum line coming from the front of the TB (front of the car)
is the one that needs to connect to the distributor.
I will plug the other one that went to a device for the air injection system.
Pictures attached if it helps the story.
1st. photo - '78 dizy
2nd. photo - vac line to dizy
3rd. photo - vac line to air inj. device
4th. photo - device that receives second vac line
http://forums.pelicanparts.com/uploa...1243568520.jpg
http://forums.pelicanparts.com/uploa...1243568715.jpg
http://forums.pelicanparts.com/uploa...1243568741.jpg
http://forums.pelicanparts.com/uploa...1243568772.jpg

Photos reversed - sorry!

Ah so, the '78 still has the air pump for emission control. A lot of people take that pump and the lines out and plug the holes in the cylinders.
But you may not be able to do that if you have AirCare inspections?

If you remove the retard line from the TB, the emission control isn't going to work.

You have the right distributor.

could someone please clarify how you are reading off your advance numbers ? I read to mark off a white paint mark every 5 or 6 mm ? wich is it 5 or 6 ? because it makes a difference once you get around a bit . also does each paint mark represent 1 degreee or 5 or 6 degrees? Also do you start at z1 ? and go which way around the puley ? I have a timing light and am ready to go

Thanks in advance , the rest of the thread is excellent and once i get these questions nailed down I am going to try it

Thanks all

On an SC 1 mm is 1 degree. I do not know if this is true for other types.
So the only thing you need to take care off is from where you start measuring the total advance from Z1 or 5 BTDC. I would only put one mark, that for total advance.

Look at the specs of your car to find the total advance permissible at high rpm as this is the only thing that matters when setting advance. When you idle the advance will then drop wherever it needs to fall. I was mistaken a long time that it is idle advance you should look at but that is indeed not the case.
I believe an SC is 23 degrees at 6000 but scroll this post to be sure or better look at the specs.
I never got my full advance but that is due to a tired dizzy.

Good luck.

Michel

5 or 6 mm is the question? Taking Michel's calculations a bit farther, for a 127mm diameter pulley, 1 degree of advance is 1.1 mm on the rim of the pulley. So 5-6 degrees is 5.5-6.6 mm.

How wide is your paintbrush? Are you making the paint mark with the pulley on the car or on the bench?

As Michel points out, the total advance at 6000 is the key. 5-6 degrees is only the rough starting point.

Oh, and the measurements are taken from Z1, to the right as you look down on the pulley as installed.

One slim white paint mark 5 mm to the right of Z1 and another at ~30 mm is good enough. The 30 mm mark would be about your max advance @ 6k RPM if the distributor advance works correctly.
Max advance might already be @ 5000 RPM.
Disconnect and plug the vacuum lines.
Paint the marks, leave the distributor loose/snug, have someone rev to 5k RPM, carefully turn the distributor to the max mark, stop the engine, tighten the distributor. Re-start and re-check the settings.

What year is your SC?
Stock?

Gunter and others,

Great thread, I am deep into it on my 80 SC dizzy. One thing I can't figure is how to detach the vacum advance?

I assume the end inside the dist is what comes out, but I can't seem to get it loose, or see insdie well enough tell what's going on. Is there anything more detailed than "slight upward movement and wiggling the inside connector arm down at the same time"?

Thanks for any tips

Kinsley

I got the vacum advance out. It was so filled with junk that it was sticking.

Absoulutely incredible how much crud was in there and how easy the advances move after cleaning an lubing.

great thread. how different is this procedure for a 1976 2.7 CIS distributor with points?

Somewhat similar. Inspect closely and use common sense to dismantle.
Only remove it when the pulley is on Z1 with #1 cylinder on compression stroke.

I serviced a few point-distributors but didn't post a write-up. Going by memory, the vacuum attaches differently to the advance plate. Don't lose the small ball when disassembling.
After cleaning the weights/springs etc. , lube the parts including the upper part of the shaft: Put a few drops of oil under the small felt plug but don't open the screw under the felt. Move the upper portion of the shaft and observe how the spring-loaded weights interact. A few drops of oil under the felt should be done as regular maintenance but is generally overlooked.

The shaft shouldn't have any radial play.

Set the clearance for the points and use a tiny bit of grease on the tab that contacts the hex on the shaft when running; lube keeps the correct gap longer.

I think the '76 has vac retard instead of advance??

yes, it has retard. i checked it by unplugging the hose from the tb and sure enough the idle went up. i sucked on the hose and idle went down. not by much but it did go down.
i will take the dizzy apart now and check those weights.

ok, got it apart. not a big deal at all.
the stouter of the 2 springs seems to have stretched. it does not hold tension whatsoever. take a look at the pic. i imagine there must be some sort of seat or something for the spring on the tab where it sits, but there is not one. the weights moved pretty freely although i did notice at first that they did not go all the way out. after i moved them all the way out to the stops then they moved more freely.
so what should i do about the spring?http://forums.pelicanparts.com/uploa...1262540901.jpg

The seat for the spring is usually a small plastic bushing on both sides. I don't see any in the picture. Looks like nothing is holding the spring.

Bosch does not supply parts. Some shops that do rebuilds make their own parts.
You cannot leave it like that.

Your choice: Find a used distributor in better shape for your year, or find a shop that rebuilds distributors.

This distributor hasn't seen any TLC for many years, lots of rust and looks like the tiny parts just rotted away?

Does the shaft have radial play?

i seriously doubt this dizzy has ever had any tlc.
there is not really any play in it. if i keep moving it around i get a slight tick but that's partly due to the vertical play. if it has play it is probably not even measurable.
could i make my own seats? i have some thin black tubing that i use for the smoke systems on my rc planes. it is chemical and heat resistance. it has about .17" od and .08" id.

Sure, you can try making these seats but..............How about the tiny clips locking the springs in place but still allow them to move?

In the old days, shops had a machine to install point-distributors and check the curve after a rebuild.

How will you check the curve?

I usually install the distributor in the engine, then use a Stroboscope and note the advance for various RPM from 2k-6k.

Make sure that the weights and upper shaft are really free.

well, it looks like i have bigger issues.
when i took the dizzy out i put it on a tray and took it to my table. did the disassembly there. brought it to the computer and took a pic. took it back to the tray where i put both springs together. now that i'm putting it back together i can't find one of the springs. everything else is there including the other spring which was taken out at the same time. i've looked everywhere to no avail. the missing spring is the one that looks stretched. so now what do i do? other than keep looking for a 1/2 inch spring on my hands and knees all over the house, garage, hobby room.

never mind. found the spring.

well, i made the spring holders. put the dizzy back on the car and the difference is night and day. i need to get a hold of a timing light to verify that all is good.

subscribing for reference

Is there a similar thread for earlier distributors ? (like for my 74 2.7) ?
Or is it that similar to this one ?

Very similar. :)

A distributor from a '74 is even easier to do than later ones if I remember correctly from a few years ago.
Remove the points (Or Petronix) and follow some of the steps. There should be fasteners under the trigger plate holding the assembly to the distributor body.

Here is your chance to document how to service the '74-'77 distributors and post a new DIY thread with pix to help others. :cool:

Go for it. SmileWavy

Thanks to this excellent thread I (absolute newbie) have taken apart and reassembled my distributor without any problems. But now that I read it through it again to confirm that I've done everything correct I got unsure on if my weights are moving as they should. I could only move them about 1-2 mm back and forth and not nearly out to what looks like the stops. How much force should be needed to move the weights?
And looking at drolas picture I'm not sure that they were all the way in either. This is how the weights in the distributor where when I put it back together.

http://forums.pelicanparts.com/uploa...1283011874.jpg

I've been thinking a bit more about this and would like to have one thing confirmed. If I hold the gear at the bottom of the assembly, shouldn't I be able to turn the rotor about 20 or so degrees in reference to the gear?

I tried to hold the gear and turn the rotor, and at first it would not move at all but applying some mild force made it turn slightly in reference to the gear so either I broke something or it loosened up a bit. Any input in how it is supposed to be would be much appreciated.

Cheers, Björn

Same question but hopefully a bit better explained:

With the distributor in place on the engine, is it possible to rotate the rotor, by hand, in any direction? And if it is, what happens when you release it?

Cheers, Björn

Björn,

My instructions are for servicing without removing the weights and springs; they stay in place and are just cleaned and lubed.
If the springs and plasic cuffs are broken and need replacing, it's a different scenario.
The springs are not the same; each has to be mated with the appropriate weight!


Yes, when the distributor is in the engine, the rotor can be moved about 15-20 degrees and snaps back because of the springs on the bottom.

The shaft is in 2 parts. Under normal operating conditions, the upper half is actuated by the weights when the centrifugal force moves them out. The springs control the amount of movement. That is the mechanical advance transfered to the rotor position when running.

In order to move freely, the upper half of the shaft needs to be lubed. Remove the rotor, remove the small felt inside the shaft, DO NOT open the screw inside, put a few drops of engine oil inside, replace felt, put another 2 drops oil on the felt, replace rotor, turn the rotor a few times by hand a little to work the oil in.

Make sure the rotor sits correctly into the notch on the shaft.

The mechanical advance is the important one. The vacuum advance has to work as well but is only there to give the initial ~5 deg "kick" when coming off idle. Not sure if Euros have vac retard but your's may be a US? Some people leave the vac retard on SC's plugged and disconnected for better running.

You can connect a Stroboscope and check the advance for every 1000 RPM and take notes.

PS: Don't forget to put a flower on Greta's stone.
Her ashes aren't there but her spirit is. :)

No retard on my euro. Just the advance

Gunter,

Thank you for explaining, I sort of figured it out by reading here and elsewhere but it is good to have it confirmed. As I described above I tried to turn the rotor while at the same time holding the gear with only a very slight movement possible. So I put a lot of 5-56 at the top of the shaft and waited. After a while I could turn the upper shaft a bit more. Some more turning and leaving it overnight made an even bigger difference.

So, today I took it apart again to find lots of rust-colored oil inside - probably dissolved from inside the upper shaft. Cleaned everything off again and now the weights move smooth all the way to the stops, turning the upper shaft in the process. Re oiled and assembled.

While it was out I have changed plugs and spark wires so I'm hoping for a noticeable improvement :)

Yes, my car is a US so there are two lines to the vacuum advance mechanism. The strobe is definitely coming out so I can set the timing.

Actually, I've yet to visit the Skogskyrkogården, but it is one of the many places I've planed to visit when I get the car running.

Thank you very much for taking the time to not only write the first instructions but also answering questions, great job!

Cheers, Björn

Subscribing for reference !! Will be doing my distributor shortly.

Thanks, Gunter!

I've been meaning to do this for a while, and it never hurts to bump this thread up.

Before: not really too bad. . .

http://forums.pelicanparts.com/uploa...1288576546.jpg


After: Much better.

http://forums.pelicanparts.com/uploa...1288576562.jpg



I imagine my distributor was probably functioning properly, but this adds a lot of (piece, peace, peas) of mind. Thanks!

The critical spot is the bearing for the Pulse Generator (805) which gums up over time; it needs to be cleaned, lubed and move real easy.

A few drops of oil under the little felt under the rotor will keep the upper part of the mechanical advance moving freely and also lube the shaft preventing excessive wear.

If the felt is missing, make one. :)

I'm planning on performing this maintenance during this week as I'm off on vacation. I'm confused on this first statement though:

Check that rotor points to the notch in the distributor housing. To ensure that it is at the compression stroke, remove the valve cover left side and wiggle the intake valve; it should be lose! If not, turn the engine clock-wise 180 deg to Z1.

I understand the Z1 pulley location and the rotor pointing to the notch - but why is it important that cyl #1 is in compression - so long as the distributor is returned to that position when re-installed?

That's only if the engine was rotated for some reason with the distributor out and one isn't sure if #1 cylinder is at the compression-combustion- or exhaust stroke.

Normally, if the rotor points at the notch and the engine is left at Z1, there is no need to check whether the valves for #1 are both loose to ensure correct position for the distributor.

Okay - took the distributor out and cleaned it up. I was surprised at the dust and dirt within the mechanism.

Mine also had quite a bit of metal filings stuck around the pulse generator - is that normal wear? I couldn't find any obvious signs of anything worn though.

Also - when reassembled, I tried to understand these instructions:
Check the vacuum diaphragm.
With a line on the advance nipple, suck on it and watch the mechanism move.
Use your tongue to hold the vacuum for a few seconds. Good? O.K.

I was unable to see anything move, but wasn't exactly sure where to look and how much movement I should see. I went ahead and installed the distributor and set the timing at idle and checked it around 6K rpm per Bentley.

Is there a way to determine if the vacuum advance is operational with the distributor installed in the car? With or without the vacuum hose connected, I noticed no difference in timing behavior.

When you cleaned the inside, did you make sure that the bearing for the pulse generator (805) moved freely?

The vacuum pod connects to the pulse generator and it can only move if the bearing is not gummed up.

The '83 SC has 2 vacuum connections: advance and retard. The diaphragm inside the vac pod moves both ways depending on throttle-setting (Vacuum from the TB)

Stock vac connection for '83 is advance to the rear of TB and retard to the front of TB. The lines have to be connected correctly without leaking due to damage.

If the diaphragm in the pod is broken, or if 805 is gummed up, the vacuum cannot work.

To check vac advance, remove the distributor cap, connect a line to the advance side of the pod, suck on it while observing the inside mechanism. You should see a slight movement of the pulse generator.

To check retard, re-assemble and re-connect everything, start the engine, when hot the idle should be around 5 deg BTDC. Pull off the retard line from the pod. You should see the timing retard about 5 deg.