[P@blo]

I came across a Chevy forum post discussing Delco distributor top bushing oiling. Seems this Dave guy might know what he's talking about and figured I would post the information and see what you all think.

https://www.camaros.net/threads/how-...arched.303273/


Question:
It will be quick of a question: How does the grease in the 5 cavities gets to lubricate the top bushing and shaft? There seem to be no path from the bushing to those greased cavities...?

Also, what exactly does the top felt o-ring do? Is it supposed to release some oil down to lubricate the shaft? If that is right... I guess the felt would get dry pretty quickly.

Dave:
The bottom bushing gets lubricated by the engine oil... but the oil can't make it's way to the top of the distributor...
The felt just under the point plate IS NOT there for the upper bushing, but, to lubricate the plate to slip over the body as the vacuum advance moves the point plate/outer reluctor.

The area under the felt, that is packed with grease, usually evacuates the grease fairly quickly. As the engine runs and heat is built up, the grease liquifies and runs into the bushing, which is a composite oilite/phosphor bronze, or open cast steel. That lube works for about a year, then is all gone. The bushing is then lubricated by engine oil mist that travels to the bushing from inside the distributor post.

NOTE: no matter what some "experts" say, not all GM bushings are oilite/phosphor bronze, more than a few were an sintered cast steel. These are the magnetic ones, and work the same with any shaft, are designed to work with lighter weight/viscosity and/or synthetic oils. The sintered steel bushings usually last far, far longer than the bronze ones do, and are more favorable to the steel center shafts. I see far fewer worn out steel bushings/shaft wear than with the bronze bushings/shaft wear.

Some main shafts have a spiral cut into them to help migrate engine oil mist up the shaft to lubricate the upper bushing.

Question:
I'd have a last question for you: I read, at different sources, that I should fill the grease cavities with gauze or felt soaked in oil. You suggest using grease. What is your opinion on that? Would you continue packing it with grease and do it on a yearly basis?
You think that any wheel bearing grease should do? Waterproof or not?
Use a good grade of waterproof wheel bearing grease for the grooves.

Dave:
I use a good grade of boat trailer waterproof grease in the grease holders, and a 30 wgt engine oil for the point plate felt lubricator. If you look closely at either the point or HEI points plate/reluctor holder, there are 3 areas that are open from the circlip area downward into the felt area. These are there so a person can add oil to the felt during normal maintenance of the distributor, that nobody seems to do, probably because the same "experts" tell others that they don't need routine maintenance, especially with the HEI distributors.

Please note, with the upper bushing the way it is, oiling the point plate/reluctor WILL NOT lube the upper bushing below the felt, as the felt is held in place by a plastic seal under it, above the grease.

All bushings are of a compound that doesn't need direct oiling/grease lubrication, MIST lube, as in air/oil in the crank case is sufficient to lube the bushings/shaft.

[geeteeohguy]

When I had mine apart on my '65 (stock cast iron unit) I used high temp red wheel bearing grease. So far, so good. Sure beats what was left of what was in there.

[steve25]

Xs two with the above for 35 years.

[Schurkey]

1. GM has used a variety of "grease" formulations, including oil-wetted sawdust in the upper bushing lube cavity. When it's me, I tend to use plain ol' white grease. No need for "high temperature" since the distributor is only going to get to 250F-ish at most, and probably not that hot. Oil temp might be higher, but the grease is held in the part of the distributor that's exposed to air to cool it.

2. Aftermarket cheap-junk distributors may have the upper bushing, and the grease well. Maybe they even pack the thing with grease. But some of those distributors AREN'T DRILLED between the grease well and the upper bushing. There is NO WAY for the grease to reach the bushing. Thanks, Communist China "Receive and Duplicate"; and thanks to the Communist Collaborators in the USA who can't manage to find these problems before they're released for sale.

3. Expect to have to fabricate a new plastic grease seal over the top of the grease well. Those used to be a fifty-cent part at any GM parts counter. GM discontinued 'em a long time ago. Now the Corvette specialty-houses get a fortune for the few remaining NOS units. The original is probably too old 'n' brittle to remove without shattering.

[P@blo]

Geeteeoguy, it kind of makes sense that the wheel bearing grease would work. The part I found interesting was the top bushing is only initally lubed by the grease in the well and then relies on oil mist lubrication to last the next 500 000 miles many factory units do. Looks like Steve has had the same results. I have been using wheel bearing grease for years no issues either.

Schurkey, thanks for your advice and input as always. For the Chinese distributors I wonder if they just apply grease to the shaft and drop it in and some grease ends-up being forced into the grease well. Maybe the bushing is of different material as well I am wondering.

The interesing part was regular oil added to the felt (and the three access holes) but never any grease has to be added to the well as regular maintenance. Seems to support what Camaros.n3t Daves post is saying. It also looks like no magic grease needed either.

[Sun Tuned]

Have a look at the top of this section in the “street- tech thread archive”.

I think you’ll find something in there that will tell you all you need to know about it, and likely more than you wanted to know.

[P@blo]

Read the sticky thread on distributor grease and had a lot of good info. Just nothing saying the grease is not really needed like Camaro Dave stated in his post. From his information the adding of grease is more a feel good exercise than one of purpose. The part that I have problems reconciling the above information is:

1) Thousands of Chinese distributors in service with no grease to the top bushing and almost zero problems supports oil mist lubrication. Bad electronics.

2) Types of bushings GM used do not require grease to function correctly. Top bushing is under low load as well.

Makes me wonder if coating the shaft with a light film of grease is all that is needed and what the Chinese do now.

Has anyone pulled a distributor that they filled the wells with grease and still has them full after a year? And then repacked the wells as needed to keep them full? If this were the case in the design, should the top bushing grease well not have a grease zerk for regular maintenance?

[Sun Tuned]

Running that dry, is equal to running an engine with no oil.

You wouldn’t do that, so not sensical to try.

It’s 1:00 pm here and I’m on way to machine shop to get a couple issues corrected. (Yes, the guy that owns the shop and I are that tight)

I’d like to come back to this later today. Plus if anyone is interested, it probably be a good thing to update some 13 year old info anyhow.

Honestly, as far as the offshore stuff is concerned, aside from the fact that I regularly correct their engineering goofs, I could really give one tinkers damn how they perceive the engineering on the junk they ship over here.

They aren’t dumb. They just figure if we’re too stupid to buy it then we deserve whatever conglomeration of junk they stuff in the box they send.

And historically ….
We keep buying it.
Bout like Charlie Brown kicking that football Lucy says she’s gonna hold…. Lol

[OG68]

It would seem to me that you would want to use a grease that has a low melting point. Since initially, the grease needs to melt and coat the distributor bushing before their oil mist takes over.

[Dragncar]

Just use some grease/lube that mixes with oil. It can not hurt, only can help. Going dry would be stupid.
Lots of overthinking being done here.

[OG68]

Didn't the cast iron versions have an oil tube?

[Sun Tuned]

In here somewhere, or at least at some point in all this, I’m sure I’ll hit in several issues that resonate with those of you reading this.

If you’re not into what I’m typing, that’s fine, nothing wrong with that… move on. If you’ve stuck around this long, let’s see how all this unfolded and where we are in 2023.

Should we even worry about packing that “grease well” with grease?
Of course we should.
Why?
Because that’s the way the GM distributors were designed to work.

Hmmm….
Well here we go.
Ford distributors don’t have anything parked up there. And they do fine….

Dodge distributors don’t either , and they’re fine….

Here’s the deal, And I could honestly spend days and at least a hundred pages on this.

First of all Ford distributor shafts are hard chrome plated day one from the factory. It’s somewhat quite rare to find a Ford distributor shaft that is worn appreciably. Their bushings are a whole different ballgame. We will include dodge stuff in that same category.

The GM shafts never were plated. However the design has always incorporated a grease well in later years or a cotton oiler wick and chamber just beside the bushing on the early early stuff.

In practice all of the GM, Ford, Chrysler designs work in their intended applications just fine.or since “just fine” really has no meaning, I guess I should say they worked well in their respective design parameters.

[Sun Tuned]

As we came into the 1955 era most of the GM distributors had up until around 1963 a felt wick oiler/tube affair that was simply a cast iron distributor with a small portion of the bushing wall ground away where the distributor shaft was exposed. On the outside of the distributor housing was a threaded hole that a steel tube with a Gitz Bros. Oiler was screwed into on the housing.there was a round cotton wick that was pushed in that touched the exposed distributor shaft and the wick held oil that was manually placed in the tube. There was an initial lube charge when built and then periodically every 2000 miles the tube was serviced with approx 15 drops of 30W engine oil to rewet the wick.

These worked wonderfully well if the service interval was kept up.

Later they got rid of the oiler tube deal and simply cast a cavity in the top of the distributor housing. GM ran cast iron housing distributors across the board approx up until 1966.
The latest Pontiac iron case distributor I’ve seen was dated early august of 1966. Then they went to aluminum housings across the board, with one big exception… tach drive corvettes used iron case distributors up until 1974. And I’m sure big C60 Chevy dump truck chassis may have used iron also.

At the inception of the aluminum distributors there was a 5 cavity grease well in each and every housing that was to be packed with grease and covered with a plastic grease seal to hold in the grease and keep contaminants out .

[Sun Tuned]

I have intentionally posted after typing awhile because in the past this server will time out and I am not retyping all this again if it gets timed out so bear with me here.

It seems GM pretty much used the same type bushing in all the iron case distributors. I’m going on a limb and gonna say something like a 660 oilite type bare bronze bushing. You can usually tell if a bushing is porous by placing it in a hot plate and watching the oil wick out onto the plate. I’ve got a couple of GM prints on these somewhere in a folder that stipulates exactly what they were.

They pretty much ran this deal until the switchover to the aluminum housings, where they kept the same deal for several years after. Somewhere up in the 1976-77 year range, we started seeing a new top bushing appear that had a chrome plated outer jacket. These are carried all the rest of the way through production until Delco ceased manufacturing of the GM housings that we know.

Early on the distributors upper bushings had a single 1/16” hole in them in line with the bottom 1/3 of the grease well. It is worthy of note to explain that the cast iron housings had more of a round trough cast in the upper housing. Therefore one single hole did fine as the hole was supplied access by the whole trough.

The later aluminum housings went to a lighter weight design with 5 distinct cavities, all fairly well sharing access to each other. These designs utilized the commonly seen bushings with 2 individual 1/16” holes opposed from each other.

Over the years the grease changed composition roughly 3 times and very early on the grease was actually a sawdust pickled in heavy weight gear oil. The grease never was of the high temp type for reasons explained later in this text.

[Sun Tuned]

The old sawdust packing was to be serviceable for the “life” of the housing . If it dried up, all that was to be done was to reset the base material with heavy weight engine oil and you were back in business.

Later on in the service procedures they stipulated if at any time the “packing” was removed refill with the GM gear and shaft lube. All the while bearing in mind to verify clear unobstructed oil holes in the bushing before filling with gear and shaft lubricant.

I’m not real sure exactly when Delco discontinued Pontiac , Buick, olds, cadillac housings but suffice it to say it obviously was a good number of years before they ditched manufacture of the Chevy distributors. The last true Delco supplied Chevy housings I can remember was somewhere around 2005. After that everything was subcontracted out and this began the appearance of the offshore stuff.

Once upon a time in a land not so far away a guy could wake up and decide since a complete distributor was no longer available from GM, well, he could build one from parts. So that necessitated nothing more than a quick trip to the local Delco supplier. A housing with both bushings installed ( the ONLY way possible to buy bushings from GM was a complete housing) was a mere 34.00. And a complete shaft assy was another 27.00.this was in 1987 dollars but the stuff was there new US manufactured for the mere taking.

This is about when the offshore stuff started showing up around 2005/6

[Sun Tuned]

With GM out of the picture, reman distributors were clearly still all over the place. This lasted several years , but the writing was clearly on the wall to be seen. Most of the reman stuff had already been redone(cycled) on average 3 times already. Well something had to give. If you got an average gm reman distributor you were lucky to find remnants of the original ID number left visible on the unit. Notice I said visible, legible was an entirely different world. This started creating all sorts of goofy problems… caps not sitting or registering on the housing correctly, etc.

About this time I’m thinking “ oh boy, this is gonna get ugly fast”.Then one day, someone sends me a new offshore Dist to fix.
Well this is cute. It’s all “new”.
It certainly looked like they were trying to make this thing look the part…since then I’ve seen better, and worse…and a bunch “in between”.

The one thing they’ve never done here, that I’ve been bitching about since day one…. What the hell happened under this pickup coil???

At first, and this is no joke. They were putting the plastic grease seals on these things shipped with no grease under them. That lasted about a year and a half. I probably worked on about 20-30 like that in a year and a half. People still had ready access to originals and somewhat sorta decent remans still.

Soon the things started showing up with no seal AND no grease. Still they were too new to see what was about to happen right off. About 3 years after these things started to be “everywhere” you looked, I get one in that had run about 15,000 miles….and the gentleman was apparently having some issue and wanted it looked at.

I pulled the drive gear off and pulled the shaft and out comes the shaft assy……
Along with it was the pickup coil…
The retainer clip….
And the bushing….
The rest of what was the housing was just kinda powdered up in what used to be the grease well cavity.!!!

This obviously won’t work anymore.

I didn’t really understand what or rather how I was gonna explain this to the guy. But when these things get hot enough they WILL friction weld the bushing to the shaft. And when that cools off, it’s good still….
Until tomorrow when you hit the key, and the starter spins the entire mess and now the housing becomes the top bushing until there’s nothing left. Wash, rinse, and repeat I guess. Pay the little eBay guy his 75.00 and start over…

It took me awhile to put numbers on it but I found that after one drives these things somewhere between 8,000-15,000 miles, one will have serious signs of imminent failure. I got one at work that had only gone approx 300 miles and it already has visible signs of distress at the top shaft.

Now, is it possible that one could design a different bushing and plate these shafts to engineer a viable workaround for this problem? Yes I suppose. But for 75.00 you’ll not see it happen.

These guys are good a copying things I’ll grant you that.
Hell, they copied the thing ringer down to the chrome plated upper bushing like what GM used on the last ones they made.

….but somebody either didn’t understand the engineering behind that desk or possibly didn’t care. GM was smart enough to drill two holes in theirs, these knuckleheads missed that memo I guess.

Of course no need to drill holes, if there’s no grease, which, you wouldn’t need if you weren’t putting in a grease seal, that you don’t need if you don’t install the grease….

The grease itself is a whole other matter. But like was said before. Don’t over complicate it, but I think one needs to understand why it’s there, for what purpose, and how to do it correctly.

I’ll get into that tomorrow.

[Schurkey]

God bless you and yours, Sun Tuned.

[Dragncar]

Originally Posted by OG68

Didn't the cast iron versions have an oil tube?

I do not know exactly. But I run iron points (triggers my CD box) distributors. Its hard to find one all worn out. Maybe they oil the bushings better. Maybe they have a larger bushing.
I just know I have found plenty of aluminum PMD distributors worn out in comparison.
All the iron units I have come across have been in good shape and they are older than the aluminum ones.
My brother was having distributor/HEI issues on his bracket sbc. I found him a iron Chevy distributor and let him use a Crane HI6 ignition box I had, cured it.
Simple is good.
Not to say he could not have gotten the HEI working well.

[P@blo]

The cast iron body points distributor and seeing little wear is what Camaro Dave was also saying. Me thinks a better bushing material is the key not the grease, or maybe a combibation of both?

Makes a guy wonder if he took two distributors, replaced the bushings and used good shafts with one filled well of grease (and holes drilled) and the other the other just a smear of grease on the shaft during install, if there would be any difference in overall wear?

All bushings are of a compound that doesn't need direct oiling/grease lubrication, MIST lube, as in air/oil in the crank case is sufficient to lube the bushings/shaft

Also, I never did suggest running a dry top bushing. The top bushing grease well focus seems like it could be splitting arse hairs as my uncle would say. The ol warm fuzzies not an ROI.

Not checking the bushing to shaft clearance or manufacturing quality before commie distributor seizing makes the lack of grease being the cause just a guess really. With everything the commies get wrong are we now assuming their machining, part quality, and installation are correct and that grease would have had that distributor bushing/shaft/housing live a long trouble-free life?

I run all dull body distributors but guys around town have the shiney lifetime warranty ones in service for years and have had no issues. Makes a guy wonder...