Lancia/Fiat/Dino Alternator Rebuild

I rebuilt the alternator on my 1976 Lancia Scorpion. I believe a similar alternator may be found on Fiat or Dino cars too.

I'll post some pictures here so one can see what is involved.

First, why replace it?

A diode failed. This casues the "Gen" light to illuminate continuously, even when the ignition is off and the key is out.
On the Lancia, the coolant hoses need to be removed to get the alternator out.

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Four long bolts hold it together.

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Fun times removing the bolt.

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The brushes come out easily from the rear. They were in excellent shape (car has 42,000k). The commutators were fine too.

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After removing the pully, fan and front plate, the rotor was still stuck in the housing.

I was able to pound out the rear bearing through two holes (already present) in the housing.

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The stator appeared to be in good shape.

Make note of the washers and bolts for re-assembly later.

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The rear bearing was stuck on the shaft and removed with a puller.

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Testing revealed the single shorted diode, but I ordered replacements for all the diodes.
I did not have any part numbers, I searched the internet until I found pictures of the appropriate parts.
These were listed by C. Obert.
I wish there had been a better way to do this, as finding the diodes was the critical portion of the repair.

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I obtained new stainless steel bearings form McMaster Carr.

I heated the housing with a blowtorch to facilitate installation of the bearings. Taking care to only press on the outer race when inserting them.

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All the parts layed out for re-assembly.


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The diode plates and stator are re-inserted, taking care the all the washers, insulators and spacers are in the right place.


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All done, ready for re-installation.

Note, when fitting the two pices of the housing togther, make sure the long bolt passes freely thorugh both mounting holes. I had re-assembled it with a slight rotation and during installation was perplexed that the lower mounting bolt would not pass freely through.

Loosening everything and a slight twist, solved the problem.

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My backup plan, if original parts could not be sourced, was to adapt NTE didoes from DigiKey:

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Originally there was only silver paint on the rear bulge, where the two holes were covered up by some sort of resin or epoxy.
When I re-built it, I painted the whole thing silver.