When I took the distributor cap off from the distributor on my 1975 Jaguar XJ-S, the three very thin screws snapped off just at the upper edge of the distributor (the part of the screws that actually has a thread. The part that goes through the distributor cap does not).
Any one out there that have experienced the same thing? How did you get the screw out of the distributor? I am hesitant to try to drill the out, since the are so thin an I donīt want to ruin the threads in the distributor.

 

Joelerik, I see 2 options at this point and I don't know how you feel about either one. From the sounds of things, these are fairly small screws, so, using something like an easy out is out of the question. So, you have to look at how thick the metal is that will be drilled out. If the metal is fairly thin (say a 1/4" or 6mm or less), then doing it by hand should be able to be done fairly easy and then you simply chase the hole with a tap to get your threads back. The big thing with this is you need to make sure that your drill is perpendicular to the distributor face so as you start drilling, you go down the center of the screw. This is where starting with a small drill bit 1/16" (or 2mm) will give you an idea of how you are doing and then you can step up in size from there until you reach a point that you fee like you can run a tap down the hole to clean things up.

Option 2 is to pull the distributor form the engine (note where the rotor is so you know where to put it back and it will also rotate some as you pull it out, so, note the final position, not where it is now). From there, you can find a local machinist that will then use their precision equipment to drill down through the center of the bolts. They will then tap and clean up everything for you. It will cost you more money, but then you don't have to worry about something not being correct.

I guess there is an option 3, but this one is very questionable about how big the screws are. You will first start with trying to soak the pieces left in the distributor with some sort of penetrating fluid (I find Kroil and/or PB Blaster are the best for this). You will then use a tool like a Dremel tool (very fine hobby cutting tool) and using the circular blade, you will make a slot cut in the top of the screw. You will probably also end up taking a small amount of metal off of the distributor so you can make the slot cut deep enough to be useful, but that is part of this process. From there, you can take a flat blade screw driver that is no wider than the screw itself and use that slot to attempt to back out the screw. This is where the thinner you can make this slot, the better off you are going to be as this will leave the most metal possible to give you something to twist against. But ,this process really is meant for something that is say a 4mm or larger bolt, not something that is really small as the cutting blade is going to take away too much material.

 

Never seen that before.

I agree with Chris's 2nd option. Not much room in there to get any drill "spot on".



Those 3 cap securing screws are a reasonable diameter, and are generally only nipped up firm, or the cap cracks. Frozen into the alloy distributor for a very long time it seems.

I have a distributor base in the shed somewhere, and will go look in a minute and measure those screw threads.

1st time tor everything I suppose, but why you.

 

Found it, no one more surprised than me, it was in the 1st container.

Mine is a HE distributor base, and M4 X 0.75, is what they are.

Since the 3 screws come pre installed on any new cap, and the caps are all the same part number, I reckon yours will be the same threads.

AND

The holes a blind, and that now explains the seizing, no lube on the screws when fitted,.