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Discussion Starter #1
I see a good amount of oil under the distributer on my 74 Spider. I have never had to remove the distributer before and would like to replace the O Ring as well as clean up the area. Would someone please share the proper procedure on removal? Electrics is not my strong point when working on these cars.
Thanks very much!
 

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I'd suggest cleaning it up first - before removing the distributor. That should help prevent getting debris inside the motor.

Next position the crank with the #1 piston at TDC on compression (remember that the piston goes to TDC twice in one cycle of a four stroke engine so make sure you have it on compression). This helps ensure you have the engine in a known position when it is time to re-install the distributor. Look under the distributor cap and make note of where the rotor is aimed. It should be aimed at the location for the #1 spark plug wire. If it is not, re-check that #1 is at TDC on compression.

Remember where the rotor is aimed so you can re-install it in the same postion. Do not turn the engine (starter motor or by rolling the car with the transmission in gear) until the distributor is re-installed.

Remove the nut holding the base plate (under the distributor housing) to the engine (timing chain case) and pull the distributor straight out.

(note: I think there is an error in the shop manual installation instruction - the crank should be positioned with #1 at TDC - the P mark, not the F mark.)
 

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Not sure its exact but I would bet it is.

distributor removal

Just make sure you re installwith the rotor pointing the same way or it will be 180 degrees out.

Good luck,

Vin
 

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Discussion Starter #4
Thanks guys. Most appreciated! Does the O Ring insert into the hole or sit between the dist. and the hole?
 

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I believe papjam always sez to install the o-ring in the block and slide the distributor into it. I know the shaft is hard to get in all the way either method but harder when installed on the shaft.
 

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Internal on the shaft
Yes, but...

If your distributor has a groove on its shaft (like the one pictured in post #6 above), then yea, it goes "internal on the shaft". But most stock distributors don't have that groove. For those, you install the O ring as flivesay says above.
 

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Well, 74 I don't know but pretty certain that's how it is on my 86 and every Bosch distributor i've seen, only a handful. I didn't think that 74 would be Marelli. I have one here someplace put can't access it. So i googled it and many images on the web for Marelli show a similar setup.

Anyone know for certain?
 

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I wouldn't take this to the bank but I seem to recall that the older Bosch dizzys with points (041, 044 & 045) have grooved shafts and an o-ring. The shafts on the later Bosch electronic dizzys (for L-Jet and Motronic cars) while grooved, do not use an o-ring. The Marelli S 103 BA, original to John's 74 Spider, does not have a grooved shaft.
No matter if the shaft is grooved/o-ringed or not, all dizzys get an o-ring installed in the groove in the timing cover. On assembly, the ring must be installed (then lubed with engine oil) on the engine, not the dizzy. If the ring is installed on the dizzy, the ring will expand so that it will not fit into groove on the engine. This will result not only in a poor seal but the dizzy drive will not fully engage the oilpump drive.
 

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The engine assembly manual in the chapter 6-10 Installing Distributor, says:

"Position rubber ring with plate and start nut (3) on cover stud. Install distributor..."......so like the photo below from an earlier car.

It is odd it says this in my S4 manual, as the dizzy and the backing plate are factory fixed with a shear screw, and I sure would not want to separate them!......however, it still means the O ring goes on the block first, as Jim says, then the distributor is fitted.
 

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Most have a groove to accept the 0 ring at the top of the casting. If it does it goes in first . That is a strange to me clamp. Everyone I've ever seen has a slot where the nut holds the clamp to the block. Maybe this a later one and I'm just old. In any event since you said you have never pulled the dizzy before there is a mistake that is easily made, just about everyone has. When you put the distributor in it may feel like it has dropped into the groove in the top of the oil pump and the rotor shaft has grabbed the other slot and will not rotate. A good way to get the "feel" is to put it in both ways and notice the difference in how deep the dizzy goes. You will get a good "clunk" when it is right. If not you can look at the holding plate and it will be sitting off the block about 3/16ths. When it's right the plate will go all the way to the block. I've always considered the side clamp a rough adjustment and have that tight before I drop the distributor in and then use the slot to set the final ignition timing. Not sure if anyone has mentioned this but if you are to lazy like me to take off the cam cover and take the chance of messing up a gasket that is not leaking you can take 1 and 4 plugs out. At TDC "P" punto superorita and firing on #1 you will not see the edges of the valves whereas on 4 you will see that both are slightly open, the overlap. I've got the RML in one and it has the 0 ring at the top just like the stock Italian distributor that rhymes with belly. I'm to lazy to go look up the exact spelling. Not having that slot is strange, that is how one sets the timing by loosening that nut (10mm crows foot) and turning the distributor. Tightening and loosening the clamp nut when on the car is a pita. Hope that helps.
Also it's a heck of a lot easier to set the points if you have them whilst on the bench rather than installed.
 

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Actually you don't have to set the motor to any specific position prior to removing the distributor. Just note what direction the rotor is pointing and put it back in the same. The drive dog is offset from center so the distributor will only go in one way anyhow. I guess if you were real determined it would be possible to pound it in 180 degrees out but really, it only fits one way.

One thing that hasn't been mentioned, if you still have the original SPICA - when you remove the clamp nut, if you drop it FIND it. Because if it didn't make it to the floor it's probably sitting on the lower stretch of the SPICA drive belt and will snap the belt as soon as you crank the motor over. The only thing you'll notice is that the car doesn't start and you could spend all day or a week troubleshooting everything you can think of before finally checking that belt.

Ask me how I know......:001_cool:
 

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Actually you don't have to set the motor to any specific position prior to removing the distributor. Just note what direction the rotor is pointing and put it back in the same.
Very true. I suggested setting it to TDC on compression for two reasons - 1) if anything gets messed up it'll be easier to unmess it. And B) if someone doesn't know what TDC on compression means and how to find it I wonder if they should be R/R'ing the distributor...

The drive dog is offset from center so the distributor will only go in one way anyhow. I guess if you were real determined it would be possible to pound it in 180 degrees out but really, it only fits one way.
Again true except the offset is not that large and people have been able to install it 180 degrees off without having to pound it back in.
 

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I know many people have gotten the timing off 180 deg when replacing cams or building a motor but the offset on the distributor drive dog is 100 thousandths ( a tenth of an inch) I have no idea how you could put that thing in backwards and not know something wasn't right. If anyone has done that then, like you say, they probably should not be working on an engine to begin with.
 

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Remembering this is a first for him, yes you can take it out at any position and the rotor will be pointing the right way but even 180 it will still catch if you try and rotate the rotor so if one is not familiar with how it feels when it drops there is still that chance. Also if you take it out at TDC the rotor will be pointing correctly but the body? Sure you can get it close but if it's at TDC you can rotate the body anticlockwise and with the ignition on note when the points open by seeing the spark. It will fire up. Actually you don't even need the ignition on just note when the points begin to open. That way it will be sure to start and then you can set the timing with the light rather than poking and hoping like I know I did when I pulled my first distributor. I don't think it fired up on the first try, maybe his will:)
 
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