Rubber bumper need?

I don’t understand what the bumper does. When swapping to an ac induction motor, do I need a bumper? Is it a motor thing?
I did not use a bumper in my hot-rod golf cart. No noise or issues.
Guess I can look at a parts list for the new ac Gems.

New GEMs dont use them, Classic GEM’s do. They take up the slack and keep a preload on motor/shaft interface to reduce noise when off throttle.

Thanks, I’ll have to let @Troyin909 know.
Any chance too much preload can cause over heating of bearings or motor?

Yeah, I recall seeing posts for others that added a dime behind the bumper and it was too much resulting in those symptoms.

I have the small rubber bumper in my motor spline. I don’t seem to have any issue with it But let me know what you guys think.

Probably nothing. I’m looking for your over heating issue.
Motenergy just answered an email, telling me the motor was certified to propel a small car at 35mph. He also asked for more information, so I will forward to you and Richard.