The 1973 maintenance guide and the 1970 CSM I have state to fill the housing lubricating cavity with SAE 20 oil as the first step of reassembly. I have also read to reassemble the distributor using high pressure grease in the gear cross-shaft/main shaft interface. Can anyone give advice as to what they have found works best? Does the lubricating cavity above get fed/replenished by the engine oiling system? Thanks for your comments.
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Tony -
Re: C3: Distributor Rebuild - Lubrication
The cavity you mentioned that your service manual refers to fill with 20 weight oil does not get replenished with engine motor oil when the engine is running. You will need to purchase the plastic seal that most likely will have to be replaced when you disassemble the distributor. You will probably find old dried grease in your distributors cavity. The lubricant in this cavity is for the upper bushing in the distributor. As to the best grease for the tach drive gear off the distributor shaft, I don't know what the best grease would be. -
Re: C3: Distributor Rebuild - Lubrication
Tony-----
The distributor lubrication cavity was originally filled with some sort of a oil-absorbant "grease retaining medium" similar to sawdust in consistency. To this was added the 20 wt oil. The medium more-or-less retained the oil in the cavity. Most folks remove this material when the distributors are rebuilt. Once removed, you cannot use 20 wt oil in the cavity by itself.
I recommened the use of grease GM #1960954 in both the distributor lubrication cavity AND the cross gear cavity. Unfortunately, this item is GM-discontinued. As a substitute, I'd use grease GM #12377985 for both applications.In Appreciation of John HinckleyComment
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Re: C3: Distributor Rebuild - Lubrication
Joe:
When I rebuilt mine, I seem to remember filling the cavity with felt packing, similar to that used for the headlight bucket pivot balls. I then saturated the felt with machine oil, and sealed with the plastic cover (seal). I hope it does an effective job, but it probably will not harden like most greases can. I am sure that it will be AOK for the modest duty cycles this car will be subjected to. Time will tell.
JoeComment
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Re: C3: Distributor Rebuild - Lubrication
Joe----
Yes, a felt washer is used in this part of the distributor assembly. As originally installed, this felt washer is installed above the plastic seal. However, I suppose that it's possible to use the felt washers in place of the original oil absorbant medium. One could pack several of these washers into the cavity in the distributor and saturate them with oil. It would likely serve the purpose.
My Chevrolet Service Manual says to pack the cavity with the "proper compound", without anywhere specifying what the "proper compound" is. Other than the grease that I mentioned in my previous post, no "compound" has, to my knowledge, ever been available from GM.In Appreciation of John HinckleyComment
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Re: C3: Distributor Rebuild - Lubrication
The Delco distributor drawings don't show this either - I use gray moly lube (ARP Assembly Lubricant) for both applications.Comment
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Well, Joe, Unless We Are Both Alchemists.......
then your guess is as good as mine. Strictly speaking, I cannot see the mechanism for ANY kind of lube migrating from the distributor housing cavity, to the upper and lower shaft bushings. Something tells me that any variations in the lubricants used for this application will probably make little difference.
JoeComment
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Re: Well, Joe, Unless We Are Both Alchemists......
Joe------
There is a 1/8" hole in the upper bushing, just at the base of the lubrication cavity. This is how the lubricant is supposed to get to the upper bushing/shaft interface to lubricate it.
The lower bushing is lubricated by engine oil.In Appreciation of John HinckleyComment
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