ZX distributor disassembly, What's this part?

[LanceM]

Well I've got a 81 ZX dizzy (modual on the side) that I want to put into my 240, I wanted to clean it up before I install it. I took it apart and found that a plastic bearing holder? had pretty much come apart/disappeared. What is this for? It looks like it is part of the vacumum advance. Can I just put a shim in the right thickness and forget about it since I'm not using the V advance? And are they're any adjustments I need to make when I reassemble it? My manuals only show 240-260 so there isn't anything this new in them...

[LanceM]

Never mind, figured it all out. I cut a brass shim to replace the plastic, now that everything is even I can see that there is no adjustment. Seeing how things are suppose to be I'm amazed that the car I took it out of was running! If one more little piece of that plastic part had come out, the distributer would have crashed! Sure am glad I decided to take it apart and clean it up first, I would not have been happy to have installed it and then have it break down the road somewhere!!!

[sjcurtis]

LanceM,

I have come across these plastics used on the internals of the factory distributor. My experience is mainly with the digital mapping distributor on the RB30 engine, the plastic in this case was a bearing shield. the bearing shield has an important job as it protects the electronic sensory equipment from the fine dust and such that is cause by the bearing in motion. primary cause of failure is normally heat. Nissan normally sell the new bearing and plastic shield as a kit. also if you find the dead bearing and plastic shield it is usually because the sensor module packed up causing you to wait for the tow truck. I am not sure exactly how the plastic failed in your distributor Lance, but please check the bearing as it could be on the way out if we are talking the same piece of plastic.

cheers

Steve :classic:

[LanceM]

Not the same thing in this case, I don't think. It's one of those "you'd have to see it" items. It was a 3 armed flat plastic disk with a bearing ball at the end of each arm, this fit between the breaker plate, for lack of a better term, and the mounting plate, allowing the vacumum advance to easily move the breaker plate which is spring loaded to apply down force between the breaker plate and the mounting plate from below. Sort of a micky mouse arrangement looking at it now, but then, they probably didn't figure anyone would be using it 20 years later. The plastic has become brittle from years of heat and just age, I'm sure when it was new it was much more pliable. Since I have locked the breaker plate in place it wouldn't have been used anyway and the brass shims give it a much more stable base than what it would have had with the plastic anyways.

[sjcurtis]

LanceM,

I understand the function of the item you have described. I have always known this item to be mild steel that has been cad plated and the ball bearing lock one piece spring steel. I would love a dollar for every one of these I have stripped lubed and rebuilt.

Sounds like you have got the best fix working. Hope you have many trouble free miles.

cheers

Steve :classic: