The Stovebolt Site Forums The Shop Area Engine Shop Grease Cup on 216 Distributor

Am I correct that the grease cup on the distributor shaft housing has some way of reducing shaft wobble? There is supposed to be a spring inside, holding a brass washer (or something) against the shaft.

If this is true (nothing I've found in the shop manual) how strong a spring do I need?

Thanks,

Have you taken the grease cup off and checked to see if the spring and plug are still there? Too bad Denny Graham is not checking in - I think he IDed the size/composition of that fiber plug.

http://chevy.oldcarmanualproject.com/parts/1929_54/154.htm

Maybe Pre'68 Dave has info on a source for the spring and plug?

Doubt it will help with the wobble of the distributor shaft. A little grease is pushed in as it works its way out from around the shaft. That's what the spring loaded plunger is supposed to do.

If you have wobble in the distributor shaft you need to either rebuild it or get another distributor. The bushings inside the housing that support the shaft is worn, and perhaps the shaft is too.

Nothing is inside pushing against the shaft. Only grease is pushed through the hole to lube the shaft.

Here is my wright-up about it on my blog.
My wright-up is more about converting a 1926 distributor to this setup, but the same applies.

As usual, very nice, Dave

Interesting. Always time to learn something new. Thanks

Roy, The grease cups that I've seen in aircraft and machine tool applications didn't have springs and discs in them. You had to turn the outside cap every once in a while to deliver the grease to the bearing. I agree that it probably would require a hefty spring to have any effect on shaft wobble.

Dave, From the material in your presentation it looks like the intent of the spring and disc is to hold the shaft against the opposite side of the bearing bore. The hole in the nylon disc would vent any pressure developed in the grease between the disc and the shaft. and the only way to get grease into the bearing would be to turn the cup like in other installations without the spring and disc.

That being said, I'd expect that the spring would be mighty stiff. Any idea what the spring K is?- since there is nothing in my distributor cup but dried grease.

Thanks, both.

I have many spare original springs.
PM me your address and I can send you one.

Make sure you clean out the grease and confirm that you can see the shaft. I have seen rebuilt distributors that have had a bushing installed without drilling the bushing so grease can pass through it to the shaft.

If the spring is stiff enough to have much effect on a wobbling shaft, wouldn't pushing it to one side of the bushing cause even more wear? Eventually would the rotor start hitting the inside of the cap? Now that I think of it, I doubt I ever knew how much clearance was between the tip of the rotor and the tip of the cap.

As Dynasoar pointed out, any grease caps I've ever worked with didn't have the spring and disc, and you had to turn the cap so often in order to make sure grease was pushed into the bore.

Interesting item here. I'll have to read and learn more.

If I remember correctly, the spring won't come out with the cap removed. You have to unscrew the body to get to the spring. It is quite possible to take the cap off, reload it and not be aware of the spring.

That is correct!

It appears to me that this part serves two purposes.
1) A way to periodically add grease to the shaft. (turn the cap in every 10,000 miles as per shop manual)
2) A way to calm down the wobble of the shaft in order to maintain the correct alignment between the rotor and the distributor cap contacts.
It does not take much spring pressure at all to calm down the wobble, since there is no side load at all at the top of the shaft and very little load at the bottom of the shaft where the gears are located.
Carl

I think the disc and spring are to maintain constant point gap rather than rotor to cap clearance.
I have not seen a broken cap or rotor as a result of the disc and spring missing.
With a distributor missing the spring you can clearly see the points gap change while shacking the shaft.
I had a 216 in my shop that had a noticeable miss on two cylinders at idle.
The customer had tried everything he could think of to fix this.
I only needed to open the hood for a few minutes to to see the problem. His distributor had a grease fitting where the grease cup should be. I had seen this before and it is quite common on a rebuilt distributor. It is also common for those rebuilders to leave the disc and spring out.
Once I put the disc and spring in the engine miss went away.

My 42 TM lists the fibre disk as PLUG distributor grease cup bolt DR-1869303

It is included in the repair kit DR-1900561

The spring is listed in the parts diagram, but not the kit. The spring is DR-1845715

So the fibre washer is a wear item, the spring is not.

My 43 GMC Delco Remey distributor does not show the fibre washer or spring.

Must be one of those Chevy things.