The driver's side window in my 87 4x4 is difficult to roll up and it does not completely seal at the top near the rear of the truck. The handle also feels loose and wiggles a lot. Would a new window regulator fix this? Should I replace the plastic behind the door panel if I take it off?

 

I'm not sure about the regulator, but I would replace the plastic. It serves as insulation and draft control. If you leave it off and go anywhere cold, you'll get a mean draft around the inside panel.

 

Thats what I figured about the plastic. Should I replace it with something thicker? I remember seeing some car insulation somewhere before.

 

I don't know if you need anything thicker, but you could certainly try it. If it works better, I'm sure that lots of us 4Runner adicts (I say that with the upmost respect in mind) would be glad to upgrade too. If you do replace it, just make sure it's as draft proof as plastic.

 

I had an 84 corolla that had a simmilar problem. The window would not go up all the way and slowly fall down from bumps in the road. The teeth on the regulator had been ground down from being used so much over time. Went to a junk yard to get another one and it worked great. Good Luck