The automatic side doors and rear hatch on my '02 Grand Caravan seem to be getting a little temperamental in their old age especially in cold weather. Are there any points or bearings or gears, etc. in the system that need periodic lubing or other r&r? It could be that the motors are just getting tired, but since the problems are much more pronounced in cold weather I was thinking that maybe cleaning and lubing the right spots might make a difference.

Thanks.