Security Permission Settings in NT4

I administer a Win NT4 Server with Win95/98 workstations. I need to implement Security Permission Settings on Drive D such that all users except for Administrator Group and Managers are allowed to delete files. I have tried using Special Access settings for files and folders give the users (RWX)(RWX) but have found that users are unable to write, add or edit files and folders. Share permissions are all set to Change permissions.