On a John Deere mower deck, on the right mandrel pulley looks like a grease sert but much smaller... do you have to add some type of oil in this area? And if so what type? Thank you [email protected]

Hi,
Some model do have zerk fittings and you can with regular automotive style grease using a grease gun. This really only serves to protect the bearing seals from contamination since the bearings on most are sealed. There are some higher end ones that are not. On those the deck will have its on model/serail number tag. Without more accurate model info, that is about all I can say.
Peace,
Clarke