I feel a bit embarrassed to even be posting this but I'm stumped. I have a 1991 350SD and have taken care of her in so many ways. I recently caught up on some basic maintenance issues and had to remove the wipers and air cowl. Upon reassembly, something just ain't right and I can't find the answer anywhere. The wiper linkage protrudes as it should through the cowl and I've positioned the small rubber grommets over the linkage shafts but with the wiper arms attached, there's too much room between the arm and the cowl. The rubber grommets almost seem to float on the shaft. It seems as if there should be something like a bushing between the base of the arm and the grommet. Perhaps someone removed these long ago but it just seems to be missing something. Might someone have a parts schematic of the wiper arm/linkage system? I just can't believe this is how this was designed.