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Click/Pop noise

I did change the gear oil 3000 miles ago in the front and rear diff, but I will check. Also, it is a full time setup and I rebuilt the transfer case 2000 miles ago.
 
What happens if you try to accelerate hard?

When you rebuilt the tcase did you replace the chain? I'm wondering if it's the chain jumping but I would think you'd really feel that. I've read that replacement chains are getting pretty hard to find nowadays so reusing an old one could be problematic.
 
What happens if you try to accelerate hard?

When you rebuilt the tcase did you replace the chain? I'm wondering if it's the chain jumping but I would think you'd really feel that. I've read that replacement chains are getting pretty hard to find nowadays so reusing an old one could be problematic.
I did not replace the chain. I searched the internet, but I could not find any replacements. The np203s don’t have many parts unless they’re from a junkyard. When I accelerate hard there is usually still is a click/pop, and I can definitely feel the vehicle stop momentum for a single second but it quickly recovers. Whenever I was pulling a trailer and trying to get back home I was trying to go as fast as possible, because it would make the noise at lower speeds. When reached the highway it was fine. It died at three lights though. If the vehicle is not completely warm or driven long enough it won’t make the noise and I can floor it with no issues. I plan to inspect both differentials this morning. I would much rather work on those than a transmission or transfer case.
 
The fluid in the rear diff looks pretty good and is still golden in color. The front diff fluid is grey and has a distinct burnt smell. Is it worth taking the cover off the front one? There was not any big metal chunks found in either one.
 
It died at three lights though. If the vehicle is not completely warm or driven long enough it won’t make the noise and I can floor it with no issues.

I’m leaning towards a tcase chain issue but this ^^ fights my theory.
 
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After watching some videos on misfires it does sound similar. It is the only thing I can find that produces a similar sound.
 
I just listened to it and it sounds like its backfiring/bucking. That also jives with it dying randomly. I’m leaning towards the distributor module.
 
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Could also be the coil (bad ground?)
Have you thrown a timing light on it?
See if maybe the timing is jumping around.
Maybe timing chain or distributor is shot.
 
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I have adjusted the timing recently. It seems to do it under load. When pulling a trailer or when transmission shifts. I will look into this.
 
I took the distributor out. I am not sure what to look for, but it definitely needs to be replaced. The plastic is all dry rotted and the last person had a zip tie holding electrical connectors together. Also, the bolt holding it down is painted a Chevy blue color suggesting this was reused before the crate engine (with now 40,000 miles) was put in. The distributor cap was replaced which made it look like new.
 
I missed the part about the engine stalling when this happens - that would not happen if it’s a driveline issue.

You may very well have an intermittent electrical problem with spark delivery like others have suggested.
 
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I missed the part about the engine stalling when this happens - that would not happen if it’s a driveline issue.

You may very well have an intermittent electrical problem with spark delivery like others have suggested.
I have ordered a new distributor and spark plug wires. I will let y’all know how it goes.
 
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