Noisy voltage regulator

[Fairlady5150]

I recently swapped the VR on my '68 1600. I was working through some charging issues, and noticed that it worked, but the contacts were badly pitted. So I decided to swap it. I noticed the new VR is making a tapping noise, usually when decelerating. At first I thought I had a serious engine issue, like a bearing. But it isn't consistent or constant, so I began looking around. I've traced the tapping to the new VR. Any thoughts on what would cause this?

[redroadster]

How loud. ? They are mechanical.
Charging right?
The solenoid constantly pulls it off charge then lets it charge fully
I bought one for my volvo 123gt once that was too noisy a hum

[Fairlady5150]

redroadster it's more of a tapping than a hum, almost a banging noise really. Loud enough to be heard inside the car with the engine running. The car seems to be charging well.

[redroadster]

They are adjustable
I wonder if you have a leaking diode on the alt.

[Fairlady5150]

They are adjustable
I wonder if you have a leaking diode on the alt.

I'm not sure how to verify this, any thoughts? The alternator was rebuilt by a local shop about a month ago.

[redroadster]

You. Osilascope the electrical to see a diode.not blocking a/c its more common on high amp usage cars which a 311 aint Its a spike on the wave form the very standard Sun tune up machine .if it leaks very much it will fry components
You can pull the cover off the regulator careful the contacts dont ground and see the charging contacts it could be the soliniod is just very strong and makes the click .
Also can put a rubber washer under the mounting screws
I dont recommend trying to adjust I think there is a tiny tool used to make the minut moves you need