Quote Originally Posted by CTN65 View Post
I thought the same, but the starters we replaced also.

I had a thought over the weekend of a weak battery not giving enough current to keep it engaged.

NTC
If it doesn't have enough juice to stay engaged, it won't turn, either. The starter field is energized by the engagement of the solenoid and drive gear, and not before. This is the nature of the GM "piggyback" solenoid/Bendix design. This is why, if the battery output is low, it just clicks or buzzes.