The 84 bus runs along County Road - you pick it up at Hardenburgh. If you drive by the intersection you'll see a bus stop there with a little covered seating area just immediately south of the light. Rockland Coach is the local company and you can call them in Westwood at 201-263-1254. I can tell you one thing for sure - the folks who answer their phone have always been extremely nice and helpful. If you thought the bus traveled on Hardenburgh between County and Knickerbocker, that's not the 84.
If you go to their website at http://www.coachusa.com you'll be able to access all the schedules. While they're not very detailed, you can figure it out from where the bus is coming from and going to. I hope this helps.