[P@blo]

Hi Tekuhn,

As was mentioned in my first post. The grease well was used for the first year until the oil mist primary lubrication takes over. Also, the shaft would be installed lubricated as well for start up so lubrication everywhere for different durations. Keeping in mind the above was the system GM used based on the part technology back then.

The waters are muddied now by the use of sintered oil impregnated bushings in new distributors (soaking in oil before install) to replace the old grease lubrication. Otherwise the internet would be full of posts of guys with seized shafts on new distributors that just stab them in and drive. And this just does not happen with the distributors being sold now. I am sure there were problems with unknown sourced parts (skip white 2010ish?) distributors that he would just send you a new one if the one he sold you crapped out or didn’t work. Probably cost $8 to make and are still floating around in garages and guys hordes today.

[Sun Tuned]

There are so many incorrect assumptions and statements s steers about in the beginning of and during this thread that theres no way I can properly address the original question until later when I get home from work.

At which time I’ll be most glad to try and clear it all up.
Theres stuff that’s close, and some stuff that’s just simply wrong.

Back later this evening….

[Sun Tuned]

After spending a good 35 minutes exposing the answer to your question, when I hit the post reply button….
Nothing!
Gone!

I now know why a bunch of the heavy hitters that used to be here ,arent here any more, and I’m about to be one more added to that list.

What a joke

[tekuhn]

Originally Posted by Sun Tuned

After spending a good 35 minutes exposing the answer to your question, when I hit the post reply button….
Nothing!
Gone!

I now know why a bunch of the heavy hitters that used to be here ,arent here any more, and I’m about to be one more added to that list.

What a joke

That has happened to me as well. Sorry about that, but I appreciate the effort....

[tekuhn]

Originally Posted by P@blo

Hi Tekuhn,

As was mentioned in my first post. The grease well was used for the first year until the oil mist primary lubrication takes over. Also, the shaft would be installed lubricated as well for start up so lubrication everywhere for different durations. Keeping in mind the above was the system GM used based on the part technology back then.

I checked a 1962 cast iron body that I have, and there is most definitely a small hole drilled through the body and upper bushing so the oil has a pathway from the sawdust to the shaft. That makes complete sense. They could use the proper weight oil for the application and the sawdust meters the flow. The aluminum bodies that I have do not have the hole. D-R would not go to all the trouble of installing the oiled sawdust in that cavity if it was not doing anything. The oil must reach the shaft - I'm just curious what the path is.

I really don't want anyone to spend a lot of time on an answer - I'm currently building a mag-pulse distributor for my '63 project and I'm faced with how to lubricate it. I just get obsessed when I see something that doesn't seem logical.

[b-man]

Originally Posted by Sun Tuned

After spending a good 35 minutes exposing the answer to your question, when I hit the post reply button….
Nothing!
Gone!

I now know why a bunch of the heavy hitters that used to be here ,arent here any more, and I’m about to be one more added to that list.

What a joke

After a couple decades or more creating posts on various forums I’ve made it a habit to hit the ‘preview post’ button several times while making a long post. That resets the timer.

Don’t type the whole thing. Do it as you compose.

Either that or copy your entire post before submitting it, if it happens to disappear you can just paste what you copied and post it again.

It ain’t all that bad…..

[jhein]

Originally Posted by b-man

After a couple decades or more creating posts on various forums I’ve made it a habit to hit the ‘preview post’ button several times while making a long post. That resets the timer.

Don’t type the whole thing. Do it as you compose.

Either that or copy your entire post before submitting it, if it happens to disappear you can just paste what you copied and post it again.

It ain’t all that bad…..

Preview post is a good thing. Even then, I can still screw it up.

[P@blo]

Originally Posted by Sun Tuned

After spending a good 35 minutes exposing the answer to your question, when I hit the post reply button….
Nothing!
Gone!

I now know why a bunch of the heavy hitters that used to be here ,arent here any more, and I’m about to be one more added to that list.

What a joke

I was looking forward to your post Sun Tunned and I am sorry to hear your reply was lost. This has also happened to me more than once and started my long replies in Word then paste in to the site.

Anyhow, I hope we do not lose you over a technical issue as you are a huge resource to everyone on this site and a great guy that shares information. Don't let jerks like me drive you off either

[TXSTARFIRE]

I was also looking forward to Sun Tuned's reply!

[68 Firebird]

Picked this up off eBay years ago.

[mgarblik]

Originally Posted by P@blo

I was looking forward to your post Sun Tunned and I am sorry to hear your reply was lost. This has also happened to me more than once and started my long replies in Word then paste in to the site.

Anyhow, I hope we do not lose you over a technical issue as you are a huge resource to everyone on this site and a great guy that shares information. Don't let jerks like me drive you off either

I have had problems with my long posts as well. It is infuriating. But we NEED you on the forum as well as others. I don't do Facebook and likely never will. Don't need the drama and the wasted time.

[Sun Tuned]

Been here too long to quit now…

Just chapped my arse.

I haven’t messed with too many distributors pre 1935 , but I’ve had my hands on some 4200+ or so built after 1950 for sure. And I can tell you guys, out of all those, I’ve never seen a factory GM aluminum housing distributor where they’ve oopsed and forgot the 1/16 holes in the top bushing . In a manufacturing deal that’s pretty damn amazing I think.

I promise you theyre there. Now I will say they’ve pressed a good many in where the hole was partially blocked by the support stanchions between the 5 cavities. That will make it look like there arent any if you’re not on your A game looking. The only way I’ve not seen any was either someone in the past replaced it, or a rebuilder replaced it.
GM got it right.

The first of the “modern cast iron distributors utilized a 660 bronze oilite type bushing that was raw bronze and had a notch cut right into the side of the bushing where a cotton wick was pushed in beside the bushing. You could literally see the lump inside the bushing bore when the shaft was removed. This wick was fed by an oiler tube and you were to put 8-10 drops of a heavy grade of engine oil down the tube at every oil change interval at around 2000 miles.

From there they went to the same type bushing without the bitch but then began packing the “well” with sawdust and still utilizing the cotton wick , it just didn’t penetrate the bushing bore. Between the cotton wick holding oil and the oiled down sawdust up top, ypu were pretty good.

Up for pretty much the whole time gm said the distributors “ needed no periodic maintenance outside an occasional 8-10 drops of oil in the oiler tube”
Well… that may in fact have been a bit optimistic. But it’s hard to argue the durability of the things early on.

[Sun Tuned]

About the time the sawdust packing showed up was when they started drilling a couple 1/16” holes in the bushing. Now this worked pretty good. I believe it actually worked a bit better than the cotton wick running up against the bare distributor shaft in that people were not quite keeping up on the maintenance an adding oil periodically as they should.

They did that sawdust packing deal for the rest of the iron housing production and I’ve never seen a factory iron housing with regular grease in it unless someone outside gm put it there. They actually ran that on into a few years of the aluminum HEI housing production. Every so often I’ll get an aluminum housing HEI that’s still got the sawdust type packing. You could actually re oil the stuff and replace the plastic grease seal and get on with it. I would however advise bending a small piece of Ty wire in an L shape and as always verifying the two 1/16” holes were unobstructed before I finished that up and replace the grease seal.

I think somewhere around 1978 they finally went to just filling the well with shaft lubricant grade grease. And I’ve seen several color variants of the grease used up until they quit building distributors altogether. That grease post I had in the street sticky section goes into greater detail on that.

[OG68]

When I rebuilt my Apr '68 distributor it did have a pair of 1/16" holes in the wells, and the wells were packed with a sawdust / dried up grease mix. As suggested I ran a fine wire through the holes.

[Sun Tuned]

All that junk out of the way, they tried several different things on the shafts to “direct” some trace amounts of oil up to the base of the top bushing. The biggest expenditure they made was a series of spiral grooving at the top end of the shaft just under where the top bushing is.
This deal lasted about 2 maybe 3 years and then you never saw it again.

This business of oil being “sprayed” upwards from the bottom of the shaft is nonsense. Theres none there , not even any decent amount of pressure at that interface anyhow. So just forget that idea.
There is a fair amount of splashing going on around that bottom bushing though, and this was used to their advantage at the bottom to lube it.

There is one situation I will mention that causes oil to pool in the top bowl of the housing… if you have a clogged or inop pcv system or your engine has suddenly developed a severe crankcase pressure event, oil can and will be forced up through the top bushing and puddle inside the bottom of the distributor housing. It is important to note distributors do not suck oil but they can be pressurized to move it up there. This is a bad deal and not a normal occurrence.

So the only thing lubing that top bushing is the little bit of base oil in that grease packed in that 5 cavity well at the top.

And folks have tried all manner of stuff at the top. Ball bearings, needle bearings, bushings , just all sorts of stuff.
Ball bearings are good for a radial application such as a water pump, but not the best for a distributor. They found that as simple and archaic as a lowly bushing is, in the end game a plain old bushing is really the best deal to put in there , as long as it’s not run out of lube or severely undersized for the application.

There will be some folks come by here in a bit and argue this point but that’s fine. I’ve seen the GM data on this, it’s not quite as glamorous for the ball bearing as you’d think. Plus as it ages out and starts to degrade the “junk” that gets produced in a sealed bearing… stays inside and helps to create more junk , faster still.

As far as bushings are concerned, the last ones GM did for the large cap HEIs in Chevrolet was the chrome looking outer jacket, that may be a sintered iron material I’m not sure… I do know when you put a couple of em on a hot plate the oil comes out the middle of the bushing ends and most assuredly NOT from the outside of the chrome plated outer jacket. This tells me if it don’t leak outside the jacket , you not readily gonna put it back in through it either. That’s why they drilled the 1/16” holes in there .

This aftermarket copied stuff… whatever they make the bushings out of , the inside finish of them reminds me of looking at an old style fresh pair of full metallic brake shoes. And when worked I can tell you they just don’t quite spin as free and smoothly as the GM distributor does..

[Sun Tuned]

The old ball bearing 985 tach drive Chevrolet distributor was a nice piece. Upper ball bearing in an iron case. There may have been a version of that for the 409 engines, but that I am not sure about. I bet our own Skip Fix would have much better insight on that.

There just wasn’t much in my opinion to be had there as far as meaningful gains over a bushing vs bearing deal. I do believe the bearing was better for high RPM no doubt, but honestly it wasn’t by a large margin. Certainly not given the cost involved. I think ultimately the bushing was plenty satisfactory for performance vs cost and likely the reason they pulled the bearing setup.

I believe Chevrolet was in fact the only gm division to incorporate an upper ball bearing in the housings of their ultra HP units.

I won’t get into the grease thing ,as I think it’s covered rather well in that distributor grease sticky at top of street section.

Maybe this will answer some lingering questions and we can put this to bed once and for all.

[68 Firebird]

you are an asset to the Pontiac community.

Gerry

[Sun Tuned]

Thanks Gerry!

I try to be anyhow.

[P@blo]

For arguments sake, does the oil coming out of the top to the distributor shaft in high oil pressure situations not prove there is a path for the top bushing lubrication via droplets?

[Sun Tuned]

Virtually none at all.

GM even incorporated some spiral grooving or channeling if you will up at the top near the bushing in an effort to “try” and direct some oil that direction….
Nope, that deal only lasted a couple years at best. If it truly worked theyd have kept that deal going. It crashed and burned graphically.

The oil mist you speak of is in fact a thing… but when you take high mileage distributors apart youll notice that there’s only oil sludge approx half way up the shaft.close, but no cigar as far as spraying or migrating to the bushing. It’s just not making it that far up there, and a Pontiac and olds, and Buick are the shortest housings in the fleet. The chevys are a good 3” longer at least. So the chevys are even worse in that reguard.

As it was designed it worked fine the way they did it. The only thing I would have told them to change would have been change “no periodic maintenance required” to at 100,000 miles replace the grease packing in the grease well around the top bushing. But then they weren’t in that department… you were supposed to buy a new car instead, or if you wrecked a distributor housing theyd be glad to have Parts network sell you a new 32.00 one.