I pulled off the rear deck panel to try to fix my squeaky rear window on my 91 4runner this weekend. It was easy and anybody that is putting up with a squeal really ought to do this right away. Just unpop the carpet panel around the edges. Get some good grease and maybe some silicon spray or antirust lubricant spray and climb in the back and close the deck behind you. Run the rear window about half way up so the bottom of the glass is exposed in the open areas of the deck sheet metal. If your window is squealling, it is probably from rust on the metal ridge where the regulator arm roller contacts the metal attached to the window lower edge. I just sprayed the rusty area to help retard rust in the area, and gooed up the ridge where the regulator rolls with axle grease. I also spayed some silicon spray in the grooves where the sides of the window track going up and down. Pop the carpet back on the deck and you're done! 10 minutes tops. Mine hasn't squeaked once since doing this and it runs much smoother and faster than previously. Get after those squeaks- this one is easy to fix.

 

Thanks for the tip jimber!!!

I used a combination of WD-40 (to remove the rust), synthetic marine grease on every moving part (to Lubricate), and Silicone spray to further waterproof the parts I didn't grease. WORKED LIKE A CHARM!!! Mine took 30 minutes.

 

I've got a squeaky window, thanks for the advice...