The sliding rear window on my '92 pickup slides very hard, the drivers side is so stuck I'm afraid I'm going to break the window, although i can slide it open. I tried apply grease to the tracks like other posts have suggested but to my surprise it has done nothing. I'm having trouble figuring out where it is binding up, is the rubber upper and lower tracks the only place it could be binding? Almost seems like the weatherstripping on the stationary window might be applying pressure to the slider. If anyone has successfully fixed the problem feel free to chime in, thanks!

Also, how easy should they slide open when working properly? Finger operation?

 

There could be dirt in the track or the track is bent, I am still digging dirt out of the track on my 4x4.

 

Use silicone lube not grease. Silicone will freshen up the material , but petroleum products will make them swell which makes the problem worse. Verfify there is a little bit of up and down play , the frame might be bent.

 

Remove the inside cover and the plastic liner, use WD-40 for cleaning the window rails and then use a silicone lube.

 

Spray Silicone works great...

 

I'm switching out my rear slider for a non-slider from my parts truck, I hate my slider.