As a follow up to my question on the attic ventilator, I purchased a
new motor with specs as close to I could to what I have (RPM is the
same at 1050, but the AMPs are 4.3 instead of 3.5).

I installed it and my only concern is that there is vibration that you
can see in the hood when the motor is running. I checked the level of
the motor and it appears to be level set within the belly bands. I
also checked the fan blade clearance and they all seem to be the same.

I don't really have a frame of reference for how the old unit behaved,
but I'm concerned that any vibration will translate to heat in the
motor. The only other thing I can think of is that the skirt to which
attach the motor to the circular perimeter has a little play...not
much, but it could be that the motor itself is vibrating the skirt,
which in turn is vibrating the hood.

Is there play in a typical system, or is there something else I should
check? The roof is fairly new, so I don't think that there's much in
the way of decayed wood, etc.

I know I could have hired someone to do this, but I really wanted to do
it myself. I appreciate your patience and replies.

Thank you,
Dave