1997 Honda Accord Hard to Shift Out of Park and into Park

It is taking more effort than it should to shift from Park to the other gears. It is also harder than it should to go back into Park. After reading the other forum articles, I checked the brake lights to make sure that the stop light switch worked and inspected the fuses for a blown fuse. All of this is okay. I removed the center console and looked at the shift interlock system. It too is working fine. The locking device moves out of the way easily when I step on the brake and let the electric solenoid valve work, or when I press a key into the manual release mechanism. After greasing up the mechanisms, it was still hard to shift out of Park either manually or with the solenoid valve so I don't think the shift interlock system is the culprit. I guess I am down to the shift cable and the transmission right? Do you have any thoughts as to what could be going on?