There is an o-ring behind the distributor that prevents oil from leaking from the hole in the head of the engine. Here is a picture. The o-ring is the black ring up against the back of the distributor body.
Mine was in decent shape but still leaking. Here is how to change it:
- Disconnect the negative battery terminal
- Etch the outline of the upper distributor mounting flange so you can replace the distributor in the exact same spot
- Remove three 12mm bolts that hold the distributor in place
- Pull the distributor straight out without moving the shaft on the back
- Replace the o-ring
- Put it back together
The back of the distributor has a shaft assembly you can see in the picture. This shaft must line up and mesh with the intake cam. If you look inside the hole in the head that the distributor covers you will see the "female" end of this shaft link.
It may be easier to handle the distributor if you remove the spark plug wires and distributor cap.
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