Sea Ray

You could possibly use some sort of rubber isolation pads similar to what are used on air compressors to reduce vibration noise.

Mine was having a similar problem until I realized it was a cabinet door next to the refrigerator that was rattling. Once I fixed that everything was a lot quieter.

The refrigerator moving parts are the compressor and the fans. Assuming there are not loose parts vibrating, then it is "easy" enough to disconnect the fans to determine if the audible noise is from the compressor or the fans.

If the fan noise is objectionable, then it is likely that the fan bearings are starting to fail. Replace with equivalent dimensional size part. Ball bearing fans are frequently used where longer service life / less audible noise is required.

Ensure that the total DC current drawn by the replacement fans does not exceed that available from the refrigerator controller, frequently 500mA from a Danfoss system.

Thanks for all of you comments/suggestions. It looks like my refrig. noise is in the fans, and probably has to do with the motors themselves, like wingless suggested. Will have to pull and replace with motors that have ball bearings. At least the work is above board. t