Final answer:
When conducting preventative maintenance checks, you should pry upward on the output shaft flange to check for d) end play in the output shaft bearings.
Step-by-step explanation:
When conducting preventative maintenance checks on the output shaft, you would pry upward on the output shaft flange to check for end play in the output shaft bearings; there should be none.
End play refers to the axial movement or play in the shaft along its length. In the context of output shaft bearings, it represents the amount of movement or clearance the shaft has in the axial direction - meaning how much it can move back and forth.
Checking for end play is important because excessive end play in the output shaft bearings can indicate worn or damaged bearings, which may lead to further mechanical issues.