Distributor: identification and maintenance question

[fizeus]

Can anyone tell me if distributor needs maintenance and eventually which parts, and how often ?

Is it a bad idea to change the distributor cap (and rotor?) or should I respect the old good ”if it not broken don't fix it" adagio?

My distributor has never been rebuilt and it's the 1973 original distributor so I was asking myself if it's time to replace its cap, even if it doesn’t show any specific problem.

Is there any other suggested ”while-in-there" parts to replace?

I have no timing light to check timing, so, can the distributor cap, and eventually the rotor, be replaced (swapping the old with a new) without performing a new timing?

Looking at PET I see two different distributor models: one from Marelli and one from Bosch.
How can I identify mine? I suspect it’s from Bosch, because the red plastic cap has a little logo (part ID or label is not visible) and I’d like to be sure before to buy.

Here are some pics of my distributor.


thanks in advance

[Bob Kontak]

Originally Posted by fizeus

Looking at PET I see two different distributor models: one from Marelli and one from Bosch.
How can I identify mine? ]

You just need a bit more time with the diagrams to digest the data base layout.

Marelli is not applicable to the 73 or the 72. See pic below.

I would change out cap, rotor and points every 10,000 miles. On this car, plugs too. All cheap even for the best quality.

As to maintenance of the distributor, I'm not the one to ask. I have read about "a drop of oil on the felt pad/rubbing block.

On the other hand, they are not complex mechanisms. If you breach the fear, you can pull your distributor out, check for free movement of the weights, check the vacuum timing pod, etc. Ask first.

Main thing is, if you wiggle the shaft the rotor seats upon and it moves side to side, you need to ask more questions so the more experienced folks can respond. That may mean the shaft bearings are tired. If they are tired and the shaft flutters around in the bearings, your contact points will not open at exactly the same time when the lobe opens them.

That's all I got.

[jason2guy]

if you work on your own car its not difficult to pull it out take it apart and reassemble
thats what i would do. ************ has a bunch of hard to get parts
you can change out all the tune up stuff without a timing light
they are cheap new and used, you should get one

[Bob Kontak]

Originally Posted by jason2guy

if you work on your own car its not difficult to pull it out take it apart and reassemble

fiz - It really is easy. However, there are basic rules that you must follow.

Once distributor is pulled you must use a timing light, though.

I say, pull the cap. Leave wires on the cap. Wiggle the shaft to check side to side. Rotate the shaft to make sure it can rotate a little and that timing weight spring tension is detectable.

Replace cap and rotor.

Only one way each can go on (cap and rotor).

When you study some, you can take on the points replacement. These being refreshed is mandatory for basic maintenance.

For fun, get your reading glasses on and a screwdriver. Open up the points a wee bit (1/8th of an inch) with the screwdriver (there is a spring that will allow this) and look at the contact points. These are machined surfaces. They should be flat. With use they become pitted and there can be deposits on one side and craters in the other. If so, they don't send the firing signal at the exact intended time with each lift of the distributor lobe.

Again, easy to do. Just "scary" for the uninitiated. We all have been there.

[E Sully]

If it is the original Bosch, it will have a number such as 0 231 169 00x stamped on it.
There are a few things to check to see if it is in good condition. My original 0 231 169 008 for late '73 cis was worn and had play in it from the fiber washer on the base wearing out. The phenolic sheet under the weights was also failing. Vacuum pods can also fail, springs and weights can become rusty or dirty and fail to move smoothly, worn and pitted points.
If the shaft has side play, a machinist can install a new bushing in the housing.
Always check the cap and rotor for pitting, and replace if worn.
Later distributors from the 74- 77 0 231 184 00x have the same advance curve and can easily be substituted.
If you want to know what is inside,
Distributor Maintenance