The repair is quite simple. First, make a note of the ignition timing presently set on your engine. Also make a mark on the distributor body and cam cover to enable your re-installation to be close to removal state. (Note the oil stain on this manifold)

Remove the distributor cap, and make a note of where the rotor is pointing. You can use a piece of tape with a written arrow, or relative position to distributor contact terminal number ... anything to assist you in replacing the distributor in the spot you removed it.
Remove the hold-down bolt, washer and bracket. The distributor drive gear is swimming in engine oil, so have a rag handy to sop up the drip to keep it off the manifold. Don't lose the washer down the hole!

A spring pin holds the gear to the shaft. It is near my right index finger in this photo. The pin looks like this:

... except that the Marelli pin is tapered. Mark the small side of the shaft and pin with a paint pen, so that you can reassemble correctly. Drift the pin out from the small side with a hammer and punch:

Remove the oil seal with a pick. Mine was so brittle it disintegrated.


Apply a thin film of motor oil or assembly lube to the new seal (available from our vendors), and press it back into position. A thin-wall socket can be used.


Reassemble the gear, reinstall the distributor, check ignition timing, and enjoy!