2001 Ford Escort 0dometer has stopped working

Odometer has stopped speedometer still works. This is my daughters car she lives 3 hours away. I would like to bring every thing I might need there when we go to see her in a few weeks. Is this usually a whole unit replace or is it a gear or cable replace.( Note we just installed a new motor 2000 miles ago it just quit now ) I pulled engine and transmission I know I need to check if something came unhooked. Thanks in advance