'89 R3500 Crew Cab 2wd to 4wd conversion & beyond

mrk5

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I did read that a siezed oil pump can cause something like this to happen; I think @6872xtc was alluding to that. My thought is an easy check will be to use my priming tool to see if the pump spins.

I don't know for sure the gear is missing. Once we realized it wasn't attached to the distributor we focused on putting it back together to get the truck off the trail. The only thing missing for certain is the shear pin.

It is funny when something like this happens you start questioning a lot of things. Like, did it have a shear pin to begin with? Probably since it's been in the motor almost 4 years and about 10K miles. But still I start to question.

I don't remember if I checked how far it dropped in before install. One cause can be the distributor pushing down too hard on the oil pump causing it to bind. Plus, as skunked mentioned, I have changed oil pumps while this distributor was in place.

I will say looking at product photos the shear pin it came with looks cheesy, especially compared to the gen 2 distributor.

Gen 1
565-100.jpg

Gen 2
565-200_0118170.jpg

I did verify they both use hardened steel gears, not just cast iron.
 

6872xtc

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The first one is a standard roll pin. Normal for the drive gears to be held on with one. Obviously there can be quality differences, and the new coiled ones are supposed to be more durable.

And yes, I was meaning that the oil pump having a problem or locking up can cause the roll pin to shear, but it usually leaves pieces stuck in one of the bores when a roll pin gets killed like that. So yes, check to see if the oil pump turns as normal.
 

Bent77

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The gen 2 looks like a spiral pin. I wouldn’t put that in my engine
 

6872xtc

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The gen 2 looks like a spiral pin. I wouldn’t put that in my engine
You don't like spiral lock pins? Would you tell your view? I don't have much personal experience with them, mostly what I have heard. Supposed to be stronger due to more layers sharing the load.
:dunno:
 

Bent77

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I see a lot of them that start coming apart, and have certainly seen more of those sheared than a standard roll pin. I change them out if I have the correct size, and have fewer failures with the roll pins in the same application
 

Wes Harden

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I too have seen spiral pins fail, 1 in particular broke on both sides of the dist shaft, one side had a little nub the would catch and the engine would run, no problems. @ minutes later it would slip and die. That was a pita to find. 1 minute you have spark the next you don't :mad2:
 

mrk5

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I think the problem was that heavy right foot run in that video. The engine was thinking, "what in the heck did we just do? I'm out of here." You have to work up to that.
I was thinking that Saturday was probably the first time I've done a snow run like that with lots of throttle since I put the 454 in. Ironically the distributor is the last thing left from the original EFI install. I put it in a couple months after the Sniper. Maybe it would have broken sooner if I had done some more rigorous snow bashing sooner.

You don't like spiral lock pins? Would you tell your view? I don't have much personal experience with them, mostly what I have heard. Supposed to be stronger due to more layers sharing the load.
:dunno:
I see a lot of them that start coming apart, and have certainly seen more of those sheared than a standard roll pin. I change them out if I have the correct size, and have fewer failures with the roll pins in the same application
I did some searching to see if this is a common issue with this particular distributor, but it's not. I did read that Fords, and I think one of the 351 blocks specifically, are notorious for breaking the shear pin on the distributor. Some posts said even the coil pins break over time because each layer cracks until they are all cracked and completely fail.
 

Bent77

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Fords also have things laid out a bit different. Not really apples to Samsungs, but not necessarily the same
 

mrk5

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I thought it was interesting more in the regards of the shear versus coil pin discussion.
 

Kay86K5

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The first pic you posted is the style pin in my distributor too when I swapped from Iron to Hardened Steel gears on my gen 6 454. Like Bent said, from my understanding that is kinda the standard style pin. And like I said in my previous post, when I was swapping gears, that thing was a bugger to get out and in. It was a very tight fit. So if this really was the failure, I'm leaning more towards possible oil pump being the culprit as well (or at least having a hand in the problem)
 

Tnsejed

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This whole thing is a blessing in disguise and the perfect opportunity to do an engine swap. With wheeling season coming pretty soon you also get to hustle to get it done. Then we can all go out for a shakedown run.
 

Bent77

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Doesn’t an 8.1 use a reluctor wheel?

That would:

Eliminate the low power
Use factory transmission controller so you could sell your old one
Eliminate the Holley stuff and the distributor
Have serpentine and use your headers and trans
 

ZooMad75

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Doesn’t an 8.1 use a reluctor wheel?

That would:

Eliminate the low power
Use factory transmission controller so you could sell your old one
Eliminate the Holley stuff and the distributor
Have serpentine and use your headers and trans
That it does. Less moving parts. Stuff a Raylar stage 2 cam in it, hot tune and it's gonna run!

Raylar sells a whipple supercharger for 8.1's that will really up the ante.

It's only money right?
 

Kay86K5

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Psshhh, even just a stock 8.1 with a good performance tune on the ECM I bet will out perform the current BBC in the truck right now. But ZooMad isn't wrong, just adding a cam to that combo really wakes up the 8.1.

Although I find it hard to see Scott do a full on engine swap just cause of some distributor problems. With the money spent on the 8.1 swap, you could put a lot of go fast goodies on the already good BBC in truck right now and probably make the same, if not more power
 

ZooMad75

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Absolutely, and there's no way your 8.1 is gonna get redistributed.
Oh, hell no. It's not going anywhere. I'm pretty hooked on the torque now. Kinda like an addict on heroin. Driving it to work tomorrow because I need a fix.
Psshhh, even just a stock 8.1 with a good performance tune on the ECM I bet will out perform the current BBC in the truck right now. But ZooMad isn't wrong, just adding a cam to that combo really wakes up the 8.1.

Although I find it hard to see Scott do a full on engine swap just cause of some distributor problems. With the money spent on the 8.1 swap, you could put a lot of go fast goodies on the already good BBC in truck right now and probably make the same, if not more power
Totally agree on all your points. I had a Raylar cam offered to come with my 8.1 and turned it down only because I didn't want to deal with getting the tune right. Between the manual trans, cable throttle local tuners that Larry went to with his burb couldn't get it dialed in. I was willing to take less power for the solid tune for the combo that we choose to run. But I did hoon around in Larry's burb when he had that cam in it. Holy cow that thing was an absolute animal. Fun to drive for sure.

While the 8.1 itself is the best factory truck big block they put out, the lack of performance parts and the insane price for what parts are out there are the limiting factors. I look at it this way, if the plan was to keep an engine fairly stock, with oem fuel injection comparing a L29 to and L18. The L18 is the top dog. But where the L29 shines is you can get any big block heads, roller camshaft, better intake/injection system to take the L29 beyond the L18 for much less money than it would cost to upgrade the 8.1.

Now one bit of a reminder on the 8.1 with all the talk of the roll pin/dizzy gear failure on Scott's big block. The 8.1 still has the oil pump driven by a dummy shaft/gear off of the back of the camshaft. Roll pin failure is still a possibility, but I've never heard of an 8.1 failing that way. They did have an issue with the oil pump driveshaft failing where it would twist the ears off that fit into the oil pump. Most of those didn't get more than 2,000 miles on them before the shaft failed though.
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