crazy happening

[geospider]

So, Just finished replacing the rear seal on the trans and all the other crazy parts:spring (broken) rubber seal and strange spacer/bushing (yes, I found an easy way of pulling the old one out) and guibo,
Went for test drive: no strange noises.
then the distributor literally BLEW apart...ad it was fairly new, less than a year and few miles.


the rotor blew off: never found on the road. Thank god i kept the old one (was leaking, but worked) and only a few blocks from home. So, do the new ones have crappy shafts that break. and are we ok with this. should have rebuilt the old. glad I kept to do that (of course havent yet)

What do we do

Geo

[RRoller123]

[18Fiatsandcounting]

Wow, Geo, that is impressive...! What do you think happened?

An idea: From your picture, it looks like one rotor screw is still there. Maybe the other screw came loose when you were driving, the rotor tilted up slightly, and this was enough to cause it to hit the inside of the cap? Or the loose screw was bouncing around in there and eventually got caught between the rotor and the cap and broke it apart?

Check your distributor shaft to make sure it doesn't have excessive play side-to-side.

-Bryan

[geospider]

Bryan,

I have no idea. A lot of bits came falling out. I have never had to worry about things being tightened up inside one of these. like I said, it is a fairly new dizzy; prob within the year, with few miles on it. Was running great. Thinking, if this is the "quality" of new ones, just rebuild your old. My old one was leaking oil up through the shaft, then drips out the little holes and of course onto the ex manifold. Other than that it worked fine. Always heard they are a pain to rebuild and new ones dont cost much; lesson learned
I doubt there is any kind of warranty on this. Am wondering if I can use some of the internals of the blown up one: like the oil seal. If nothing else, a practice one to take apart.
Geo

[18Fiatsandcounting]

I hear you, Geo. Without knowing what actually caused this, we don't know if there is a problem with your distributor or you had a bad rotor and/or cap. Or a screw came loose as I mentioned.

Here's what I would do (for what it's worth): Take out your distributor. Buy a new cap and rotor. Install the rotor. Put a large dab of grease on each of the 4 contacts inside the cap, and install the cap. Slowly spin the rotor by hand a couple times. Remove the cap and see if you can tell from the tracks in the grease how close the rotor tip is getting to each of the 4 contacts. I'm guessing the clearance should be at least a millimeter or so, but that's just a guess. Also check to make sure the clearance at each contact point is about the same, that is, if one contact point appears to have very little clearance and the one directly across from it has several millimeters, your rotor may not be centered in the cap. Of course, before you install the distributor back on the engine, clean off all the grease from the cap and rotor.

-Bryan

[RRoller123]

deleted.

[geospider]

yep, sheared right off. and not sure where it ended up either.
The only thing I can do with the "new" broken one if use it for any other parts, assuming they come out nice. I wouldn't trust the bushings: who knows if the shaft itself also bent. dropping the old one back in was easy enough: roadside repair. But I know the leak is coming soon enough.
Called Ar, they will get back to me about what can be done. Maybe nothing, but worth asking.

Geo

[18Fiatsandcounting]

OK, now I'm confused. I thought the rotor that you had for your '79 looks like this:
https://autoricambi.us/ignition-rotor-1979-85/

So the shaft didn't shear off, just the rotor assembly that sits on top of the centrifugal advance mechanism. Or am I missing something?

-Bryan

[PaulC]

I had a replacement cap and rotor from rock auto that had mis-molded contacts in the cap and an overly long contact arm on the rotor.
Did this to the cap contacts


Here's the new rotor on the right with a proper replacement on the left


Made a clack clack sound when rotating the dizzy for timing adjustments.

[geospider]

I have heard of that. Mine had run perfectly fine for months, no noise, etc.
then...pow...backfire and die.
had to be a pretty good force to shear the shaft like that. And/or, not the best metal shaft.

[18Fiatsandcounting]

Maybe I'm just dense, but I still don't see where the distributor shaft broke. Your rotor (or one of the screws that holds it to the baseplate) hit the distributor cap internally, breaking them both apart. Other than the broken cap and what's left of the rotor, the top of the distributor in your picture looks normal to me.

What am I missing?

-Bryan

[tima01864]

What is holding the rotor Bryan? I just looked at a spare i have, you are right it looks normal.

[RRoller123]

Deleted. My error, this is what happens after a 14 hour day.

[geospider]

Bryan,
I think you are correct.
But; when I turn the gear, the pints on the shaft hits the pick up. Now, I have taken the one I replaced to see how normal that might be, but it seems a bit, well, abusive. I don't think these are supposed to whack each other. correct me if I am wrong

BTW: sent pics to AR, they are sending me a cap and rotor. with all the force, I am concerned about the health of the rest of it.

[geospider]

Bryan,
On another note; Taking the drive line out again to do the rear seal of trany and guibo replacement; actually the spring and rubber gasket and spacer replacement (the spirng was broken)
Anyway: actually put the drive shaft back in with no issues at all. remember my past struggles. I GOT THIS

geo