Rear windows need help coming up

Both of my rear windows will come up about half way and then they need help by lifting them while holding down the switch to get them the rest of the way up. Any idea what is causing this? I haven't taken the panels apart yet but was wondering if anyone has any thoughts before I tear into this project. Could the motors be failing or do they just need to be greased?

Thanks,
Steve

 

Your motor gear boxes need to be greased as well as all sliders/channels and rollers. Buy spray lithium grease

 

George,

Thanks for the reply, I will try that.

Thanks,
Steve

 

did it work?

 

I haven't had the time yet to get to it. With it being in the low 20's here in NJ I haven't been very motivated either. I will try it soon and post back.

Steve