['97ventureowner]

I've haven't had the opportunity to tear apart my wiper system yet, so I'm not sure if the Venture uses the same system other older GM vehicles that I have owned or worked on use. This system has the wiper arms that are splined, and they fit onto a splined shaft. I was thinking that maybe they are wearing out with age and use, so they maybe be slipping after prolonged use. If you use your wipers a lot, (if you live in an area that receives a lot of precipitation,) then this could be a cause. The simple fix might be what you are describing, or you might replace the wiper arms. You could try to take off a wiper arm and see if the splines on either surface are wearing out. I seem to remember from previous repairs that the arms were usually the first to go, maybe they were made that way with a softer metal. If that doesn't work, you could check the linkage from the wiper motor to the arms. I shudder when someone talks about the wiper system on these Ventures as it looks like a pain in the ass to work on, with a great deal of the system hidden in the engine compartment.