They're a sealed unit and very forgiving. The motor sits inside the pot with the refrigerant gas / oil, and it is only the terminals in the connection block that are external. ( For several years the Company that I worked for had a Refrigeration department and all the maintenance / regassing etc was done in an adjacent area in the workshop )I have two freezers, one which is kept for emergency use. Both must be at least 40 years old. The front opening one in the kitchen cannot be replaced with the same as they no longer make that size as a stand alone unit. The top opening one got flooded in a particularly high tide as it was in our workshop at sea level.
I sprayed the motor unit with fresh water then plenty of WD40 followed by contact cleaner. That was about 20 years ago and it still works when required.😊