Spitfire New alternator doesn't fit - '78 Spit

[lilifer_13]

Okay, I am a complete newb to working on cars but I am a quick learner and generally have a good head for mechanics. Part of the reason I decided to purchase my aunt's '78 Triumph was so I could rebuild it, learning as I go. Well, I've already hit a roadblock on my very first project.

We had it into a local British car place when we initially bought it 2 summers ago and he did some basic fluid flushing and redid the brakes to ensure it was safe. We drove it around all summer (2020) and stored it over the winter. Well, this summer on about the second trip out, it wouldn't start after sitting in a parking lot for about 45 minutes. Battery is new and good. I realize it could be many things, but it seemed to be the alternator as we were able to push start/pop the clutch and get it going again.

I ordered a new alternator from Moss, triple checking the part number and cross referencing it with their instructions on how to make sure you're ordering the right part. I pulled out the old alternator and when I went to put the new one in, it didn't fit. They are different sizes with the new one being wider. Pic below shows new on the top and old on the bottom. I'm stumped. There is no way for me to get this new one to fit. It just doesn't add up. Help a girl out.

Many thanks.
Lily

 

[Gliderman8]

You could take the old one into a competent alternator shop for them to rebuild.
Just curious… how did you determine the original one was not charging?

 

[DrEntropy]

Lilly, if you look at the back "ear" on the new alternator, you will see an insert in the rear mounting hole, it is meant to "broach" through the hole as you tighten the thru-bolt and tighten down to hold the unit tightly against the bracket. As long as the pulleys are both the same distance from the face of the alternator and line up on the crank and waterpump pulleys, it should work.