Yes, it can be used for both the top and bottom.
Sorry to have to come back to you again but my simple replacement exercise has not gone well. When I installed the new ones, only one had a freely working spring. The others jammed. Wheels turn ok, but no, or. difficult, spring movement. Any suggestions?
Thanks, Ron K.
Check to see if the adjustment screw is getting hung up in the door rail. That could be what is preventing the spring action. Also, see if the cut out opening were the wheel is inserted is bent and holding up the wheel.