vinyl handles

Hello,

We do carry a few surface-mounted sash lifts that you might be able to install on your sliding windows. Feel free to look through our selection here. If you decide to give it a try, be very careful not to hit the glass in the window sash which makes the installation holes. 

With that being said, the difficulty you're experiencing could be from the window rollers or by debris clogging the track. I would recommend checking the rollers for damage before making any kind of modifications to the window. Thanks for posting and let us know if you have any other questions.