Killed my distributor

DodgeT · May 12, 2015

Took a drive in my Coronet this weekend and heard a big snap, then the engine puttered out shortly thereafter. I pulled over and figured my distributor had just gotten a bit loose or something.

Well, after several attempts at adjusting the distributor location I realized I might have a bigger problem. Unscrewed the distributor bracket and she came loose - very loose. The distributor shaft actually snapped in two.

This is a Pertronix Distributor and I've been pretty happy with it thus far. I called them and they are sending me out another.

Here's my issue - there is a collar and pin on the shaft and they are no where to be found when I look down in the cam valley.

If you look at this image you can make them out:

Will these things safely make their way down into the oil pan if I can't find them? Would pulling the timing cover help me locate them?

This is a fairly stock 440 if that helps. The distributor wasn't overly loose, but not torqued either. Could that snap the shaft?

Hemi Rebel · May 12, 2015

The only way the shaft is going to snap is if it seized in the distributor. Never seen that happen.

Bigal75 · May 12, 2015

You'll want to find the missing parts.

DodgeT · May 12, 2015

Bigal75 said:
You'll want to find the missing parts.

hmmm... So where do I start? Could use some good advice here.

66Satellite47 · May 12, 2015

Better pull the intake, valley pan, timing cover & find the parts. Not sure how the bearing/bushing would be able to seize. Be sure to check the oil pump drive too. May need to pull the pan.

71airgrabberRR · May 12, 2015

I'd begin by removing the intake manifold. Can tell 100% from your picture but it looks like you have a big block??? The temperature sensor looks like its on a small block though.
If you have a B or RB engine the intake is very easy to remove. Unbolt the carb. 8 bolts later its off. No coolant to worry about leaking.
If you are lucky you will find the missing parts laying in the lifter valley. If not, they may have made their way down to the oil pan.

- - - Updated - - -

I'd be taking a close look at the oil pump and distributor drive gear too.

- - - Updated - - -

The lifter valley will be accessible after the valley pan gasket is removed. In order to remove it, there will be three bolts on each end of the block. These bolts will secure the end rails which look like a flat steel bar.

Mr.SpeedFreak · May 12, 2015

Damn that is crazy! Between my junk pertronix ignitor II, and now this, pertronix is not looking like a quality brand imo..

DodgeT · May 12, 2015

71airgrabberRR said:
they may have made their way down to the oil pan.

- - - Updated - - -

I'd be taking a close look at the oil pump and distributor drive gear too.

- - - Updated - - -

It is a Big Block. Any chance those parts would wash out with draining the oil if they are in the pan?

The distributor drive gear looks fine from what I can tell. The oil pump is a high volume Melling. What else should I be checking on the oil pump? My oil pressure has been great.

I guess the intake may have to come off first. I sure hope that stuff is in there if I do. How hard is removing the oil pan with the engine still in the car?

Thanks for the help, guys.

- - - Updated - - -

Mr.SpeedFreak said:
Damn that is crazy! Between my junk pertronix ignitor II, and now this, pertronix is not looking like a quality brand imo..

I guess I can't say yet. I will say that up until now the distributor has made it a better car.

71airgrabberRR · May 12, 2015

Chances are very slim that any of these parts will drain out with the oil. Even if they did make it to where the drain plug is located, the drain plug hole would limit the size of the parts that would come out.

Removing the pan with the engine in the car isn't too awfully bad. It will involve unbolting the engine mounts and lifting the engine up a little. You may also have to turn the crankshaft so that counter weights are up into the block on the #1 & #2 cylinders. Try searching here on FBBO as I'm sure there will be a thread or two started on the subject.

As far as inspecting the oil pump and distributor drive gear goes:

Anytime you have an engine part failure it creates small fine metallic particles that get suspended in the oil. Some of these pieces can make their way past the pickup tube and create problems with the oil pump gears. Disassembly, inspection, cleaning of the oil pump is cheap insurance to help prevent a problem down the road.

- - - Updated - - -

Plus I would check the relief valve / spring in the oil pump as well while you have the pump apart. Just a good inspection / cleaning is all you may hopefully need.

It may be helpful to get some service manual or book on Big Block Chrysler engines. They will give you other valuable information on things like torque sequence and values for various engine fasteners.

- - - Updated - - -

On the distributor drive gear look at the hex end to see if it has twisted. If the gear is held in place with a pin I would suspect the pin as well.

MarPar · May 12, 2015

fffffffff:censored:!!!

Meep-Meep · May 13, 2015

Here's my theory as to what happened. And I have never seen this before either. The distributor shaft must engage the oil pump drive gear but not be put in a bind. It's possible something is a miss and when the distributor clamp is tightened it forced the shaft into the oil pump drive gear. If the bushing in the block is worn or loose (not uncommon) the oil pump shaft might wobble a bit and move the distributor shaft with it. The roll pin hole is naturally a weak spot and a good place to break if the shaft is subjected to fatigue. You can see how the distributor body being locked down tight will concentrate the force into flexing the shaft or wearing out the bushings.

When you get your new distributor in make darn sure the housing bottoms out in the block before the shaft bottoms in the gear. This will be tricky to do and will require a good feel or simply put the distributor in lightly snug and crank or start the engine and see if the body wobbles around. Again, there should be no influence on that shaft except rotational. If need be make shims to put under distributor body to raise it up.

The Horvaths · May 13, 2015

I've seen badly cracked and brittle nylon bushings. It is possible that one (yours) may fail altogether. That would allow the shaft to ride up inside the distributor body. Then the rotor or centrifugal weights/plate could strike somewhere inside and wham! Now the shaft shears at its weak point and the roll pin goes wherever.

I also suggest that you'll want to find EVERY piece. A magnet may help to retrieve the roll pin.
Check oil pump and drive, check cam shaft drive gear for broken teeth, and definitely replace distributor. The distributor's body or internals may well be stressed now. I pull mine to re-curve them and, when I do, I replace the old bushings with the newer flanged bushings. I shim to ~ .005" end play and move on.
Good luck, we're pulling for you!

To Meep-Meep's point, tugging up/down on the rotor should still allow you to feel minor end play when the distributor is fully clamped down.

68 HEMI GTS · May 13, 2015

start removing stuff till you find all the parts. like the other said intake first. oil pan would be second. timing cover will probably be a waste of time.

Dako · May 13, 2015

I'm thinking you had a defective shaft (heh...I said shaft). The reason I say this is that there is much less metal at the 'spade' end. That's where it 'should have broke' if there was binding.

Meep-Meep · May 13, 2015

The Horvaths said:
I've seen badly cracked and brittle nylon bushings. It is possible that one (yours) may fail altogether. That would allow the shaft to ride up inside the distributor body. Then the rotor or centrifugal weights/plate could strike somewhere inside and wham! Now the shaft shears at its weak point and the roll pin goes wherever.

I also suggest that you'll want to find EVERY piece. A magnet may help to retrieve the roll pin.
Check oil pump and drive, check cam shaft drive gear for broken teeth, and definitely replace distributor. The distributor's body or internals may well be stressed now. I pull mine to re-curve them and, when I do, I replace the old bushings with the newer flanged bushings. I shim to ~ .005" end play and move on.
Good luck, we're pulling for you!

To Meep-Meep's point, tugging up/down on the rotor should still allow you to feel minor end play when the distributor is fully clamped down.

Sort of. Only because the distributor cam or reluctor is on a separate stub shaft and often has movement in the thrust (up and down) direction as well. If all is well you can feel a stop in two places - where the main shaft collar stops against the bushing and where the distributor cam stops against that little clip under the rotor.

To get a better idea of where the parts went look at a bare block (if you or a friend has one handy) to see the general path.

71airgrabberRR · May 13, 2015

This should help.............. This is my 440 for my 72 SSB that is fresh from the machine shop, but still needs me to get off my butt and put it together..............

- - - Updated - - -

- - - Updated - - -

The first picture shows the distributor drive bushing. As mentioned above these sometimes wear.

- - - Updated - - -

The large open area just behind it leads to the top timing gear / chain.

- - - Updated - - -

The open area to the left goes to the camshaft / lifters.

- - - Updated - - -

I normally grind off the excess flashing then clean the block real good afterwards.

- - - Updated - - -

- - - Updated - - -

This picture shows the bushing from where the distributor is installed.

- - - Updated - - -

- - - Updated - - -

This shows the area behind the timing cover. You can see the excess flashing in the top of this picture. This is the area where some of the parts could have gone, but they still will end up in the oil pan most of the time.

- - - Updated - - -

The large open area above the camshaft is where they likely went.

- - - Updated - - -

- - - Updated - - -

This picture shows everything installed. This is looking from inside the lifter valley area forward.

- - - Updated - - -

- - - Updated - - -

This is a closeup of where the distributor drive gear and bottom of the distributor mesh together. This is probably where your problem started. If it is too tight here it can cause binding.

- - - Updated - - -

- - - Updated - - -

This is how your distributor drive gear should look when you are ready to reinstall the distributor. Have everything lined up on #1 cylinder firing and make sure the notch is aligned front to back.

- - - Updated - - -

- - - Updated - - -

Hope this helps.............

DodgeT · May 13, 2015

71airgrabberRR said:
This should help.............. This is my 440 for my 72 SSB that is fresh from the machine shop, but still needs me to get off my butt and put it together..............

- - - Updated - - -

Thanks for taking the time to respond, guys. I'm darn near positive I had a new distributor bushing installed. Isn't it brass?

Taking off the intake doesn't sound horrible. I'm not overly keen on removing the pan, but whatever. I will start with the intake and pray I find the parts.

I have an oil leak that seems to come from my oil pump area anyway so I don't mind removing that and checking it either. I do have a factory service manual

I think the challenge in all of this is I only have about 50 miles on it after my restoration and I keep running into hold-ups. First a collapsed lifter, than a fan through a radiator, leaking gas tank, now this. Will I ever have a reliable car?!

Thanks again.

Cranky · May 13, 2015

Yeah, pull the intake and see if there's anything up top but it will be very difficult to go fishing with a magnet from up there to the bottom but you can do some from the timing cover area. Use a long strong mag. If you chose not to pull the pan, I would install a magnetic drain plug for a little added insurance plus you can do some fishing through the drain hole. Fish for any junk that you can. Pull the pump for sure and if you see any damage to the rotors, pull the pan and inspect bearings. If you have a windage tray, that may make things harder to do. If you find the shaft up top, fit it to the shaft that's still on the dizzy and see if there are more shaft pieces missing. If not, you will only be looking for the collar and pin. If you're lucky, the filter caught any small junk that may have come loose from the broken shaft. Cut it open and see what's in it. Oil is forced through the paper from the outside part of the can. If you can open the filter like a tin can, you should see any junk in the can or on the paper. If the pump looks good and you find nothing in the filter, then you should be feel pretty good. If you can't find the roll pin, placing a strong flat magnet to the bottom of the pan can work in keeping it there. The last time I collapsed a lifter on a 383, I fished out the old lifter though the head and replaced it and said screw the retainer etc and ran it without any issues but I think I would fish pretty hard for that roll pin.

Mark B · May 13, 2015

I have seen a billet distributor fail like that. The diameter just under where the cap sits was larger than the stock unit. The distributor was hitting the head which cocked it to the side enough that after a hundred miles or so the shaft snapped just like yours.

DodgeT · May 13, 2015

Cranky said:
I think I would fish pretty hard for that roll pin.

Pulled the intake. Everything looks clean up top. I ran my finger in all oil puddles and didn't see any metal. The distributor gear moved freely up off the camshaft, too.

So can I put the top back together? I suppose I should pull the pan....yuck. I've got a new oil pump gasket on the way so I can check that.

Killed my distributor

Active Member

Well-Known Member

Well-Known Member

Active Member

Well-Known Member

Well-Known Member

Well-Known Member

Active Member

Well-Known Member

If it weighs, it pays

дворянин

Well-Known Member

Well-Known Member

Well-Known Member

дворянин

Well-Known Member

Active Member

Banned Henchman #27

Well-Known Member

Active Member

Similar threads