Jack R. wrote:
> My question is, are the splines cut into the new arm upon attaching to the
> shaft, or should the arm of had splines on it.

The wiper arms have soft metal inside where they connect to the splined
shaft.  Splines are cut when you tighten the nut on.

It's likely that your old arm is still good as new splines are cut after
you clean all the soft metal from the shaft.

Mike