Wednesday my friend/mechanic and I put on my "new" alternator. It was actually a used alternator from a '95 Maxima. The alternators were very slightly different... the '95 Max alternator had a different bolt spacer and it was overall about 1/8" bigger... almost not noticeable. We got it all installed, and its been driving perfectly since then, but I've noticed that the belt / pulleys are jiggling a little when the car is on. Nothing serious, but they aren't perfectly smooth. My mechanic said that it's completely normal, but I wanted to make sure he wasn't just saying that to cover up a poor install.

 

i noticed it about mine also 2 days ago but my boy (comparable to the mad scientist) its normal for then to wiggle a little