Longevity of OEM distributor?

[texas tough]

my vote is pull it and do a very good inspection,, the star wheels get hairline cracks in them, the magnets lose thier magnetism, the shim above the drive gear wears, the gear wears, the shaft gets gunked up inside the housing, the electrical module gets brittle, the insulation falls of the wires, ect.. you really dont realize how crappy a truck is running until u put a new distributor on. the distributors on these trucks are so important for the truck to run right. the duralast gold replacement ones are very good with lifetime warranty. 140.00 they come with everything, including a brass terminal distributor cap and a rotor that actually fits properly, no slop. when the shim and gear wears in the distributor, it creates slop,. it then pushes the rotor up against the top of the cap, wearing out the caps. slop will also cause misfires and carbon tracking on your sparkplugs. if u see a black line on your plugs coming down from the electrode, the plugs are partial misfiring. after I replaced my distributor, I put an empty aluminum can on top of the air cleaner and started it. I let it warm up good, and watched the can. the can barely moves at all. just a tiny vibration. I showed my neighbor and he was impressed at how well it ran with over 200.000 miles on the original engine. never been in the engine.

 

[Schurkey]

The Napa distributors are a pretty high quality part. I believe they’re still made in their South Carolina plant, here in the good ol’ USA.

I'd be very surprised. However, the local store doesn't stock one, so I can't look at the box to find out for sure. Of course, the web site is totally useless for finding Country of Origin info.

www.napaonline.com/en/p/NNDNNDST1830?impressionRank=1

https://www.napaonline.com/en/p/NNDNNDST1830?impressionRank=1

Unless you have zero value of your own time or only want a bare minimum repair, there’s really no reason to mess around with rebuilding one these days. You get a completely new body (instead of replacing worn bushings), a completely new shaft (instead of replacing a worn shaft), new pickup coil (common failure point), new ignition module (another common failure point), and a new cap and rotor (which is likely due for replacement anyway).

If you think you can get all that and still save money including your labor, I’d love to see it.

Probably moot at this point--I don't know of a source for distributor shafts which is why I bought the lot of three shafts on eBay a year or two ago. And since the magnet on the shaft is the main reason for rebuilding...about all there is now is new or commercially-rebuilt distributors. From what I'm seeing on the NAPA web site, the price for new vs. rebuilt is the same; and the rebuilts have a ~$40 core charge.

My problem is that the Chinese modules and gears are probably high-failure junk. I've heard of offshore distributor housings that weren't drilled for proper lube. So if the whole distributor is Chinese or based on Chinese parts...

So my recommendation is to pop the original distributor apart for cleaning and inspection. If the magnet isn't cracked, and the shaft isn't scored at the bushing areas--and the bushings aren't sloppy (if the shaft is good...the bushings probably are, too) you've got a great candidate for "rebuilding" which typically means "clean it, slap on a new pickup coil, and put it back together." I'd rather have a 200,000 mile Genuine GM module than a brand-new Chinese module (assuming the GM module still works.)

Broken magnet (common) or scored shaft/worn bushings; and the thing is probably done since shafts are hard to come by now. SAVE THE MODULE if it still works right. Throw it on a shelf in the garage, or put it in the glovebox.

 

[Nick_R_23]

I’m not sure where your “Chinese junk“ rant originated from, but the Echlin distributors, as well as the internal parts such as the ignition module, are USA made.

If you bought the $25 eBay special no-name distributor, I’m sure that’s actual Chinese junk.

I also don’t know why you’d bother spending the time doing a half ass rebuild and only replacing the pickup coil and not the ignition module, as both are common failure points. Used GM modules are absolutely not worth saving - straight into the trash. Just like Texas mentioned, these distributors are very important to the runnability of these engines, nearly as much as the ECU itself. For $150, there’s probably no more part better to replace on a TBI engine.

 

[Caman96]

I’m not sure where your “Chinese junk“ rant originated from, but the Echlin distributors, as well as the internal parts such as the ignition module, are USA made.

If you bought the $25 eBay special no-name distributor, I’m sure that’s actual Chinese junk.

I also don’t know why you’d bother spending the time doing a half ass rebuild and only replacing the pickup coil and not the ignition module, as both are common failure points. Used GM modules are absolutely not worth saving - straight into the trash. Just like Texas mentioned, these distributors are very important to the runnability of these engines, nearly as much as the ECU itself. For $150, there’s probably no more part better to replace on a TBI engine.

That’s good to know!

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[Schurkey]

I’m not sure where your “Chinese junk“ rant originated from,

If you thought that was my "Chinese junk" rant, you haven't been paying attention.

but the Echlin distributors, as well as the internal parts such as the ignition module, are USA made.

I'm VERY pleased--and surprised--to have that confirmed.

If you bought the $25 eBay special no-name distributor, I’m sure that’s actual Chinese junk.

No, thanks. Closest I've come to that is being willing to salvage a "Summit" house-brand that I bought used, from a guy on this forum.

I also don’t know why you’d bother spending the time doing a half ass rebuild and only replacing the pickup coil and not the ignition module, as both are common failure points.

Because the module--IF (big IF) it does fail--is ultra-easy to replace with the distributor in the vehicle. Pop two screws for the cap, rip off the rotor, three electrical connectors, two screws holding the module to the distributor. Wipe the old heat-sink compound off the mounting plate. "Reassembly is the reverse..."

Used GM modules are absolutely not worth saving - straight into the trash.

Wow.

 

[98 Nitro]

Those Napa dizzy are same as Standard Auto Parts I put in my 98 last year it is made in USA .

 

[thegawd]

Holy A distributor that's still made in North America? that's probably the last of their kind.

do they make one for the vortec? I couldnt find a North American made distributor when I reluctantly bought one that was absolutely made overseas.

Hey, I was brought up to fix things, not throw them away. If I didnt fix things I couldn't afford half the shìt I got.

some people save thing from being thrown out and others throw things out. I also find that the same people who throw things out, also dont have the time to properly recycle things and probably tossed that used distributor in the trash.

 

[delta_p]

I went ahead and put a new OEM distributor in my '96 at 167,000 miles. No problems with original and worked well, gear looked good, just grungy and rusted from the Alabama humid environment over the years. Trucks been with me since new.

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[eran tomer]

TBI distributor.

Disassemble for cleaning and inspection.

Gear condition
Shaft condition including magnet
Housing bushings (2) condition, and upper lube reservoir
Pickup coil condition
Module condition
Cap 'n' Rotor condition

Clean everything, replace parts as needed. fresh heat-sink compound under the module, reassemble. Don't forget to also inspect the wire harnesses (2) that plug into the module.

I'm thinking that there's a lube reservoir on the TBI distributor just like the older coil-in-cap HEIs. If I'm remembering this correctly, the plastic shield over the lube reservoir is brittle and no longer available. The lube itself has been everything from oil-wetted sawdust to white grease, to "special sauce" with a GM part number. This reservoir lubes the upper bushing. Cheap Chinese HEI distributors are known to have a lube reservoir...but the Commies "forgot" to drill the holes in the housing that allows the lube to reach the upper bearing. Brilliant! A lube reservoir that's entirely useless as the lube is prevented from going where it's actually needed.

The only two of these that are of genuine concern are the shaft/magnet and the housing bushings. If the shaft is scored, the bushings are probably toast. If the magnet is cracked, you need a new shaft. Shafts and housings are probably not available new, except as Communist Chinese knockoffs of dubious quality.

The only part I'd surely replace would be the pickup coil. They're not expensive, they are a pain in the *** to replace--the distributor shaft has to be removed; so replace the pickup coil when you've already got the distributor apart for inspection.

Better to have a "good used" Genuine Delco distributor than a brand-new Chinese knockoff; especially in the quality of the module.

this is a new housing i bought, the thing in red circle is what you refer to as lube housing? it doesn't have a plastic shield on it.

i got also a new shaft, it has some surface rust on the lower part so it won't go into the housing. it's been awhile so i can't return it. do i need a new shaft?

 

[1990Z71Swede]

Sooo yeah... Bought this one as a spare. Excellent condition othervise. No slop in the bushings , gear looks real nice etc. Can I get a new magnet somewhere? The good thing is the seller had two, I bought them both for $60 thinking it would double my chances... It did. The other magnet does not appear to be cracked... yet
Still... Would really like to fix this one too if possible.