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My '79 bronco with a crate 351m with 3000 miles recently quit starting. I moved it one day (it ran great) and now it won't start. It backfires through carb pretty bad. I was told to check timing, upon that I noticed distributer gear wasn't turning with motor cranking. I pulled distrubuter and the pin in the gear was sheared off, so I put an old distrubetor in and it did the same thing. I pulled timing cover off and the timing chain has major play in it, so I ordered a new timing chain set. Is there anything else I should look for that I would cause a problem like this that I need to look at while this is apart?
 

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when you say 'it did the same thing' - you mean it sheard the pin on the second distributor, or just that it wouldn't start?

If it sheared another distributor pin, i would check to see that the oil pump is working correctly. If that somehow jammed up or you're using heavy wieght oil and its really cold there could be a lot of resistance at the oil pump drive, causing the pin to sheer.
 

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The timing chain has 'major play' after only 3000 miles??? That makes no sense...

Anyway, you need to pull the pan and the oil pump and figure out what happened to make the pump load the dizzy gear so badly. The oil pump is only thing that loads that pin that keeps failing..
 

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I had thoughts about the oil pump causing this, so I will have a new one on its way to be installed, hopefully this combination (oil pump and timing chain set) will fix my problem. Yeah I was wondering about timing chain slack too being that fresh of a motor. Thanks for the help.
 

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I had thoughts about the oil pump causing this, so I will have a new one on its way to be installed, hopefully this combination (oil pump and timing chain set) will fix my problem. Yeah I was wondering about timing chain slack too being that fresh of a motor. Thanks for the help.
X3 on the oil pump, get a new pump and pickup tube. Be sure to clean the heck out of your oil pan. Any metal shaving or little bit of debris can cause the oil pump to lock up. A new cam would not be a bad idea. That cam gear has sheared off two distributor gears....I bet it is toast.

Good luck
 

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how long do oil pumps typically last? How do you know if it is going out other than the dis. gear takin a shit?
Typically, an oil pump will outlive the engine. A failure that takes out a distributor gear is usually the result of debris in the engine getting sucked into the pump. A small sliver of steel like a pulled thread from a stripped oil pan drain plug, or a little chunk of nylon from a crappy oem ford timing set. It only takes a little piece.

To prevent this issue, do as the engine builders all recommend:

1) Be religiously clean when building or working on an engine.
2) ALWAYS replace the oil pump pickup tube whenever the pump is replaced.
3) A magnet in the oil pan can be a life saver.
4) Change the oil yourself! Quickie Lubes are notorious for stripping pan plugs
 

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Typically, an oil pump will outlive the engine. A failure that takes out a distributor gear is usually the result of debris in the engine getting sucked into the pump. A small sliver of steel like a pulled thread from a stripped oil pan drain plug, or a little chunk of nylon from a crappy oem ford timing set. It only takes a little piece.

To prevent this issue, do as the engine builders all recommend:

1) Be religiously clean when building or working on an engine.
2) ALWAYS replace the oil pump pickup tube whenever the pump is replaced.
3) A magnet in the oil pan can be a life saver.
4) Change the oil yourself! Quickie Lubes are notorious for stripping pan plugs


So my oil pump is about 20 years old and it works great... should I leave it when I rebuild or replace it? Would I need anything else or just the pump?

Also the magnet is a great idea, I need to do that. My oil is always full of shit, gritty in texture, a high-power magnet may help a ton.
 

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So my oil pump is about 20 years old and it works great... should I leave it when I rebuild or replace it? Would I need anything else or just the pump?

Also the magnet is a great idea, I need to do that. My oil is always full of shit, gritty in texture, a high-power magnet may help a ton.
If it were my truck, I would replace the oil pump and pickup tube at a rebuild.
 

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A new cam would not be a bad idea. That cam gear has sheared off two distributor gears....I bet it is toast.

Good luck
Doubtful, the 1/8" roll pin in the distributer gear that sheared will go away a long tome before any cam gear damage can occur.

I went through a bit of this last summer. Seized the oil pump... it had ingested something it didn't like and all the internals tried to weld themselves together when the clearances went away.

I'm a fanatic about keeping stuff clean during engine assembly but made a critical error. I had lost a cam and gone clear back through the engine, cleaned every passage and galley etc etc.... Bolted the oil pump and pickup back on that had been through the cam failure :banghead.
It only had a couple of hours on it so I didn't think to replace it..lesson learned.
 

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Doubtful, the 1/8" roll pin in the distributer gear that sheared will go away a long tome before any cam gear damage can occur.
That has not been my experience. The failures I have experienced destroyed both gears, but they were never on the 335 series engines. These failures were the result of a mis-machined block on a 2.3 turbo (thanks ford!). The oil pump did not sit perpendicular to the distributor, causing the drive shaft to bind every revolution. No cam was involved here as this is an OHC engine, but driving the oil pump and distributor is an auxiliary shaft of exactly the same design a cam would use.

I suppose you could take a chance that the cam is OK. Best case, you could get away with it and all will be OK. Worst case, it will fail again and you will need a new distributor, cam, lifters, oil pump, pickup, etc.:banghead
 

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That has not been my experience. The failures I have experienced destroyed both gears, but they were never on the 335 series engines. These failures were the result of a mis-machined block on a 2.3 turbo (thanks ford!). The oil pump did not sit perpendicular to the distributor, causing the drive shaft to bind every revolution. No cam was involved here as this is an OHC engine, but driving the oil pump and distributor is an auxiliary shaft of exactly the same design a cam would use.

I suppose you could take a chance that the cam is OK. Best case, you could get away with it and all will be OK. Worst case, it will fail again and you will need a new distributor, cam, lifters, oil pump, pickup, etc.:banghead
Way different configuration between the 2.3 and the 335. You can also do an easy visual inspection of the cam gear with the distributor pulled on the 335.

Interesting about the poorly machined block on the 2.3 I'll be building one of those this coming month for our sand rail.
 

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Way different configuration between the 2.3 and the 335. You can also do an easy visual inspection of the cam gear with the distributor pulled on the 335.

Interesting about the poorly machined block on the 2.3 I'll be building one of those this coming month for our sand rail.
You are correct, the configuration is different on the 2.3, but the principal is identical. Two gears at right angles drive the distributor and oil pump. The main difference here is what caused the issue. For my 2.3 it was a mis machined block, for the 335, debris probably caused the failure.

Watch those turbo 2.3 blocks! The trick is to bolt the aux shaft, oil pump, and distributor in place and then spin the aux shaft by hand. If you feel any binding, back off the oil pump bolts a little and see if the binding goes away. If it gets better, you might have a block issue. Good luck with your sand rail, I really hope you do not run into the problems I had!
 

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BW, thanks for the tip. I'll have a good look at the alignment as you suggest.

I agree the principle design of the gear drive is the same. I still contend that with a good visual inspection of the cam gear a person should feel very comfortable about not having to change out the cam-lifters etc just because of an oil pump failure shearing the 1/8" roll pin in the dist. drive gear.

I'm looking forward to the 2.3 build.
 

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BW, thanks for the tip. I'll have a good look at the alignment as you suggest.

I agree the principle design of the gear drive is the same. I still contend that with a good visual inspection of the cam gear a person should feel very comfortable about not having to change out the cam-lifters etc just because of an oil pump failure shearing the 1/8" roll pin in the dist. drive gear.

I'm looking forward to the 2.3 build.
We are going to have to agree to disagree on the cam. I have terrible luck, so I tend to err on the extreme side of caution. I say replace the cam, because if it was my truck the SOB cam would destroy itself and send shrapnel through the engine. But for everyone else, they would probably get away with it!

2.3 can be a pretty wicked little beast, I assume that is a turbo job going on your sand rail? If so, you will love the feel of boost when it hits.:beer
 

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Well I guess we can continue the hi jack here a bit longer....

No I'm not going to turbo this one I have a pair of 44 IDF Webers sitting on the shelf waiting for a home. This one is going to be a fairly mild motor. It will be built with the idea that when my wife wan'ts to jump in it and turn the key it'll fire and run.
When everything else in camp is broke I want to be able to jump in and play. I have a tendency to continue my bronco "DEVELOPMENT PROGRAM" by breaking parts on something of a regular basis.
I intend to work pretty hard on the suspension for the rail before I get carried away building HP.

I respect you opinion on the cam change it can often be better to error on the side of caution.
 
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