New minn kota very noisy

I bought a new minn kota endura C2 55lb thrust trolling motor and first time out it sounds bad. Like maybe brushes or bad bearings. Only used it one time. I've had many last 45yrs and none were this noisy. Any one have similar experience?

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Google Minn Kota 55 lb Eliminator Prop Nut. $22 on Amazon 

Takes out a lot of the vibration and runs quieter.

Gone through 3 in about 6 years. They seem to be cheaply manufactured but they are so inexpensive I almost consider them disposable. I’ve had noise issues with some off the bat & all eventually. I happily pay more for a better motor but not a lot of options out there in a transom mount.

Yes  its a transome mount. $249.

Is it a transom mount? Like $219 for a 5 speed & $249 or so for variable?